Some believe the pieces come from wreck of the Titanic - which sunk in 1912 
 
 Mystery continues to surround the origin of the 100-year-old fragments of rubber that have been washing up on the shores of Britain and northern Europe for the last two years. 
 
 Last week, conservationists cleared more than 100 rubber sheets, two rolls of rubber, three rubber ingots and several tablets from Chesil Beach in Dorset. 
 
 Some theorists believe the pieces could date back to the Titanic - and may have risen to the water's surface after being contained for more than a century in the lost wreckage of the ship - which sunk in April 1912. 
 
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 Discovery: Izzy Imset, a local dive shop operator at Chesil Beach in Dorset, found this collection washed up on the shore 
 
 Most of the pieces are engraved with the name Tjipetir, an early 20th century rubber plantation in west Java, Indonesia. 
 
 And their perfectly-preserved quality is alarming environmentalists and sparking fears over why supposedly biodegradable materials have remained completely intact. 
 
 The rubber blocks and sheets are in such fine condition that they could have come from a ship that had just sunk. 
 
 But the material they are made from was popularly used around a century ago. 
 
 Conservationist Steve Trewhella said it is worrying that the pieces, some about one metre long, are in such good condition considering the rubber is meant to be biodegradable. 
 
 The pieces are made from gutta percha, a form of latex made from the sap of a tropical tree of the same name. 
 
 Theory: Some believe the blocks may have come from the Titanic, pictured, which sank in April 1912 
 
 The pieces are made from gutta percha, a form of latex produced from the sap of a tropical tree with the same name. It was used to make a wide range of items 100 years ago 
 
 Most of the pieces are engraved with the name Tjipetir - an early 20th century rubber plantation in Java, Indonesia 
 
 Worry: Their perfectly-preserved quality is alarming environmentalists and sparking fears over why supposedly biodegradable materials have remained completely intact 
 
 It was used to make a wide range of items 100 years ago, including teddy bears' noses and golf balls, although the most common use was to insulate underwater telegraph cables. 
 
 Other sheets found washed ashore are marked 'Senawang' which was also an early 20th century rubber plantation in Asia. 
 
 POSSIBLE EXPLANATIONS FOR 100-YEAR-OLD WASHED UP RUBBER Since perfectly-preserved pieces of 100-year-old rubber began to wash up on shores around northern Europe, several theories have been put forward to explain their mysterious appearance: Some believe the pieces could have come from the Titanic, which sunk in 1912. 
 
 Another possibility is that the fragments came from a Second World War cargo ship on it's way from Asia to England. 
 
 Similar pieces have washed up on beaches in Cornwall, Jersey, Normandy in France, Holland and Germany and there is a Facebook group, called Tjipetir Mystery, dedicated to the mysterious rubber. 
 
 One wild theory is that the pieces could have come from the Titanic. 
 
 Gutta percha tablets were listed on the famous ship's manifest before it sank on April 15, 1912, but there is no evidence these pieces would have come from the Titanic wreck. 
 
 Another possibility is that they came from a Second World War cargo ship on it's way from Asia to England. But as the cargo is valuable, the name of the ship will not be revealed until the salvage operation is complete. 
 
 Mr Trewhella said: 'It's a bit of a mystery. What we do know is that the rubber came from this plantation in Indonesia 100 years ago and it was destined for Europe and various parts of the world, but we have no idea what it would have been used for. 
 
 Tjipetir is the name of an early 20th century rubber plantation in Indonesia (pictured) 
 
 'This was before plastic existed and gutta percha was used for a variety of products from the soles of shoes to insulation for early telegraph cables. 
 
 THE 'UNSINKABLE' SHIP WHICH SANK IN 3 HOURS Dubbed the 'unsinkable' ship, the Titanic famously struck an iceberg and sank in under three hours on April 15, 1912. Of the 2,224 on board, 1,517 passengers and crew perished. It lay unseen on the ocean floor for decades, until 1985, when an American-French expedition identified its final resting place 329 miles south-east of Newfoundland. The wreck, which was split into two sections 2,000ft apart, has now been the focus of research by scientists and historians for 25 years. 
 
 'There is a ship that went down off the Isle of Scilly a hundred years ago that we think it could be. 
 
 'Some people have speculated that it could be from the Titanic, which was carrying this product when it sank. 
 
 'In reality it seems quite unlikely but we do get objects washing up from as far as north America. 
 
 'It could be that a shipwreck is gradually disintegrating, and as the hold is becoming more exposed the cargo floats to the surface and washes ashore. 
 
 'Some of the pieces have goose barnacles on them which indicates this rubber has been floating on the surface for some time as they only attach to flotsam on the ocean surface. 
 
 'The thing we find most worrying is that this is biodegradable rubber and here it is, 100 years later, in near perfect condition. It is astonishing that this product has remained intact for so long. 
 
 Goose barnacles found on one of the rubber mats washed up suggests it had been floating on the surface for some time as they only attach to flotsam on the ocean surface 
 
 Washed up: Seaweed and flotsam can be seen riding a wave at Chesil beach in Dorset 
 
 'It still looks as good as the day it was made which raises concerns about the litter we are making now. 
 
 'Scientists and various organisations make assumptions about how long things will take to break down but they don't really know. 
 
 'We're leaving a long-lasting legacy and I think people will be picking up our rubbish in a thousand years.' ||||| Image copyright Tom Quinn Williams 
 
 For the past few years, 100-year-old rubber-like blocks from Indonesia have been mysteriously washing up on beaches in the UK and northern Europe. The Titanic has been suggested as one of the possible sources - but now a beachcomber says she may have solved the puzzle of the Tjipetir blocks. 
 
 In the summer of 2012, Tracey Williams was walking her dog along a beach near her home in Newquay, Cornwall, when she spotted a black tablet on the sand, made of something resembling rubber. 
 
 It looked like a large chopping board and the word "Tjipetir" was engraved into it. Weeks later, she found another such curiosity on a different beach alongside bales of rubber, washed up in a cove. 
 
 Her curiosity piqued, she began to research the origins of these mysterious blocks. What she learned included stories of shipwrecks, an infamous World War One tragedy and the Titanic. 
 
 It also transpired that these blocks had been appearing on beaches across northern Europe, baffling everyone who had found them. 
 
 Image copyright Other Image caption This image appears to show Tjipetir blocks on an Indonesian plantation in the late 19th or early 20th Century 
 
 Image copyright Louise Mamet Image caption Louise Mamet found this block at Dunes de Sainte Marguerite in Landeda, France 
 
 Image copyright Jan Jacob Westerbeek Image caption Jan Jacob Westerbeek found this block in Bergen aan Zee in the Netherlands on 8 December 2013 
 
 Image copyright Adam Adamson Image caption Adam and Marina found a Tjipetir block on a small island, Out Skerries, off Shetland in August 
 
 There has been speculation in the press as to the source of the washed-up blocks, with the Daily Mail and the Times recently running articles. The French press covered the story in April also. 
 
 But Williams believes she has worked out the source of the mystery - and it matches what the UK authorities think too. 
 
 Image copyright Tom Quinn Williams Image caption Tracey Williams with two washed-up Tjipetir blocks 
 
 The word Tjipetir turned out to be that of a rubber plantation in West Java, Indonesia, which operated in the late 19th and early 20th centuries. 
 
 The blocks were not strictly rubber - they are most likely gutta-percha, the gum of a tree found in the Malay Peninsula and Malaysia. It was used in the 19th and first half of the 20th centuries to insulate telegraph cables on the seabed. 
 
 Before modern plastic began to be widely used, gutta-percha was also made into such items as golf balls, teddy bear noses, picture frames and jewellery, among many others. 
 
 Williams began charting her progress on a Facebook page, which led to many people coming forward to reveal their own gutta-percha finds, often made when they were cleaning their local beach. 
 
 These were not only around England and Wales but also in Shetland, the Channel Islands, Spain, France, the Netherlands, Germany, Norway, Sweden and Denmark. 
 
 Along with these blocks, bales and rolls of rubber are also being washed up. 
 
 There has been speculation that the gutta-percha could be coming from the wreck of the Titanic. "A French newspaper covered the story and reported that the Titanic had been carrying gutta-percha," Williams said. 
 
 "I checked the ship's manifest and discovered that it had indeed been carrying gutta-percha and bales of rubber. There was much wild press speculation about this afterwards." 
 
 Image copyright Jonathan Johansson Image caption Jonathan Johansson and his mother Lisbeth (pictured) found a block in March in Heestrand, Sweden 
 
 Image copyright Friederike Wegert Image caption Friederike Wegert and her children found a block in March 2013 on Borkum, an island off the German coast 
 
 Image copyright Jose de Cora Image caption Jose de Cora found a Tjipetir block in San Cibrao, north-west Spain in August 2013 
 
 Image copyright Corentin Perrin Image caption Corentin Perrin found this in November at Brem sur Mer in France when he fell on to "curiously hard" water 
 
 Then, in the summer of 2013, Williams had a breakthrough. 
 
 She was contacted separately by two people - who did not want to be named - and both pinpointed one wreck as the source. They knew of a salvage company carrying out recovery of cargo from Japanese liner the Miyazaki Maru, which had sunk during World War One. It had been carrying the Tjipetir blocks. 
 
 It sank 150 miles (241.5km) west of the Isles of Scilly. 
 
 Image copyright Other 
 
 Miyazaki Maru 
 
 Built in 1909 in Kobe, Japan 
 
 Ocean liner of 8,520 tons 
 
 Sunk on 31 May, 1917 during a voyage from Yokohama to London by German submarine U-88 
 
 Was carrying cargo and passengers - eight people died 
 
 Now situated 150 miles (241.5km) west of the Scilly Isles 
 
 Source: Wrecksite 
 
 "I was told that when salvage work is done, the cargo they are looking for is pulled out in large amounts, and the gutta-percha and rubber bales have been released from the ship's hold as a result," Williams said. 
 
 "So both my sources told me that shipwreck is where those items are mainly coming from. I've been shown evidence supporting this." 
 
 Image copyright German Federal Archives Image caption Walther Schwieger also sank the Lusitania 
 
 But Williams isn't the only person who thinks the gutta-percha is coming from the Miyazaki Maru. 
 
 The government's Receiver of Wreck, Alison Kentuck, the official who administers wreck and salvage laws within UK territorial waters, also says it is most likely the blocks are indeed cargo from that ship. 
 
 "When we are made aware of wreckage we conduct research to find the owner," she said. "We look at the age of the items, where they could have come from and examine any markings. 
 
 "Our findings with these particular items pointed towards that particular wreck. So although we have not confirmed it, the Miyazaki Maru is our favoured possibility as the source of the washed-up blocks." 
 
 The Miyazaki Maru was sunk by a German submarine, U-88, captained by Walther Schwieger, one of Germany's most successful U-boat aces. 
 
 Schwieger was also in charge of another German U-boat which, in May 1915, sank the RMS Lusitania, a liner bound for Liverpool, carrying 1,924 passengers and crew from New York. That notorious event led to more than 1,100 deaths, including more than 100 Americans and is thought to have hastened the US's entry into the war. 
 
 Oceanographer Curtis Ebbesmeyer, who specialises in tracking flotsam, says the Tjipetir blocks may be washing up on beaches for centuries. "Based on the findings so far, they are clearly being fed into the hemispheric ocean circulation. It only takes 25 years for flotsam to go around the world, and they've probably been around long enough to go around the world three times. 
 
 "They're still in good condition after all these years, which is unusual. They're probably one of the great pieces of flotsam that people may be finding 100 years from now." 
 
 Ebbesmeyer also said various gyres - or ocean currents - may pull the blocks from Spain across to the Americas "mirroring the same route that Columbus took" before possibly ending up in Florida. The ones found in the North Sea "should go up past Norway, turn east past the top of Siberia, go through the Bering Strait into the North Pacific and go all over from there". 
 
 Several people have also reported finding Tjipetir blocks back in 2008, before the current salvage operation is thought to have begun on the Miyazaki Maru. 
 
 One person has come forward to say they found a block more than 30 years ago and used it as a chopping board to gut fish on their fishing boat. 
 
 "Many ships would have been carrying gutta-percha, so it's possible that the cargo is coming from more than one source," says Williams, who is writing a book about the Tjipetir story. "It is being seen as pollution - and I clean debris from my local beaches all the time - but the gutta-percha is a natural product, so it does degrade. I've seen disintegrated blocks on the beach." 
 
 "Perhaps other companies are salvaging material from World War One wrecks too. It is possible that some of it is from the Titanic? I don't know." 
 
 Walther Schwieger picture courtesy of the German Federal Archives (BArch, Bild 134-C1831 / o.Ang. / CC-BY-SA 3.0) 
 
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– From Britain to Spain to Denmark, rubbery blocks have recently washed up on beaches, all bearing the same word: Tjipetir. It's still not certain where each block comes from, but a woman who found one while walking her dog in England has a pretty good idea, the BBC reports. After Tracey Williams posted on a Facebook page about her investigation into the matter, two individuals who haven't been publicly identified told her about a Japanese ship sunk 150 miles west of Britain's Scilly Isles during World War I. The Miyazaki Maru carried the blocks, and it has recently been subject to salvage work, resulting in their release, the sources explained. The blocks have their origins in Indonesia, where they get their name from a 19th- and 20th-century rubber plantation in West Java. The rubber-like stuff—likely a tree gum called gutta-percha—was once used for such diverse purposes as insulating cables and making golf balls. Williams' theory is supported by a British official in charge of the country's wreck laws—the Receiver of Wreck, as she's known. But "many ships would have been carrying gutta-percha, so it's possible that the cargo is coming from more than one source," Williams notes. One of those sources could be the Titanic, which listed such blocks among its cargo, the Daily Mail reports. Interesting pieces of history, but not so appealing to conservationists: "The thing we find most worrying is that this is biodegradable rubber and here it is, 100 years later, in near-perfect condition," says one. (In other weird beach finds, a two-headed dolphin recently washed ashore.)