南洋商报
Even before the fire was extinguished, rumours of arson were already spreading rapidly. Some eyewitnesses reportedly saw "young Chinese men" throwing flaming torches onto the roof of an attap house. On 28 May, Nanyang Siang Pau reported that the Criminal Investigation Department had questioned 2 residents living near the epicenter of the fire. By early June, the Department had questioned over 10 eyewitnesses regarding the fire. On 9 June, the police had arrested a suspect, but he was subsequently released due to the lack of concrete evidence supporting the eyewitness testimonies. After this report, there was no further coverage of the investigation into the cause of the fire. In addition to arson, other speculated causes of the Bukit Ho Swee fire include a gangster fight gone wrong and fire from a cooking stove. The cause of the fire has remained a mystery to the present day.