The 30-storey tower being built to house the State Audit Office was reduced to rubble in seconds when a 7.7-magnitude quake struck neighbouring Myanmar on March 28, killing thousands in Thailand's wartorn neighbour.

The tower was the only building in Bangkok to collapse, and the speed and suddenness with which it fell has raised questions about the quality of the construction.

"A Thai court today issued arrest warrants against three groups, comprising 17 people, related to the collapse," Police Lieutenant-General Siam Boonsom told AFP.

He did not give details of those targeted by the warrants, but Thai media reports said they include staff from Italian-Thai Development (ITD), one of the firms building the tower.

Authorities say they have recovered 89 bodies from the rubble of the collapsed tower, with seven people still unaccounted for.

The project was a joint venture between ITD -- one of Thailand's biggest construction firms -- and a Chinese conglomerate.

Initial tests by Thai safety officials last month on steel rebars -- struts used to reinforce concrete -- recovered from the site found that some of the metal used was substandard.