Miners dig for diamonds in the Marange fields. A report by Partnership Africa Canada (PAC) alleges that at least $2bn has gone to a 'parallel government' in Zimbabwe. Photograph: Tsvangirayi Mukwazhi/AP Diamonds worth at least $2bn (1.26bn) have been stolen by the Zimbabwe president Robert Mugabe 's ruling elite, international dealers and criminals, in "perhaps the biggest single plunder of diamonds the world has seen since Cecil Rhodes", a watchdog has claimed. The Marange fields in eastern Zimbabwe were discovered in 2006 and are one of the world's biggest diamond deposits. But funds from diamond sales have not reached the state treasury, says a PAC report, published on Monday to coincide with a Zimbabwe government conference on the diamond trade in Victoria Falls. Instead there is evidence that millions have gone to Mugabe's inner circle. "Marange's potential has been overshadowed by violence, smuggling, corruption and most of all, lost opportunity," says PAC. "The scale of illegality is mind-blowing" and has spread to "compromise most of the diamond markets of the world." The report, Reap What You Sow: Greed and Corruption in Zimbabwe's Marange Diamond Fields, describes the $2bn lost to the Zimbabwean treasury since 2008 as a "conservative estimate". Tendai Biti, the finance minister, said in his latest budget he had been promised $600m in diamond revenue for the national treasury to help rebuild neglected hospitals, schools and other public services. Only a quarter of that pledge has been received, he claims. The PAC names Obert Mpofu, mines minister since