The Foreign Office said British officials were working on the basis that 217,000 people had died or were unaccounted for. The figure, which a spokesman said was based on new United Nations estimates, is approaching the estimated 225,000 who died in the Asian tsunami of 2004.

Channel 4 News reported that one Whitehall official had said that the Government believed that the number could be as high as 250,000.

It came as The Daily Telegraph learned that thousands of survivors are reportedly being used as forced labour in Burmese government camps.