It said its conclusions – made into a documentary it produced and aired by Al Jazeera - were based on a five-year study and revelations by a recent Myanmar army defector.

Undermining ties with US

On Al Jazeera

Myanmar's military ambitions

The Myanmar foreign ministry's statement, noting that Jim Webb, a US senator, had postponed his trip to Myanmar in light of the allegations, said the accusations were aimed at undermining renewed dialogue between the US and Myanmar.

Webb, the chairman of the US Senate Foreign Relations Subcommittee on Asia and the Pacific and a leading proponent of greater engagement with Myanmar, postponed his visit following the Voice of Burma report, saying it was a bad time for such a visit because of the new allegations.

The report said tunnels and bunkers were being built with North Korean help [DVB]

The foreign ministry said the allegations were based on "information provided by army deserters, defectors and dissidents which are inaccurate, unfair and unreliable".

A separate foreign ministry news release said the defector, Sai Thein Win, who had smuggled out files and photographs, was a captain in the army and had a degree in power engineering from State Technical University in Moscow.

It said he was an army deserter who had been absent from his job since February 2010, but did not specify where he had worked.