The 30-storey tower crumbled seconds after a 7.7-magnitude earthquake hit Myanmar on March 28, killing thousands in Thailand's wartorn neighbour.

The tower, meant to house the state audit office, was the only building in Bangkok to collapse, killing 89 people on the site, mostly construction workers. The speed and suddenness with which it fell prompted a legal probe.

Thailand's Office of the Attorney General said a case has been submitted to a criminal court, with a decision expected in a matter of months.

"Investigators agreed to indict 23 individuals and legal entities over professional misconduct and forged documents," it said in a statement.

The indictment included 16 individuals and seven firms, and also listed the names of people representing some of the accused companies, which include an architectural firm and a Chinese construction business.

Further details of the allegations were not released.

However, separately, justice department investigators have previously said they were probing the quality of construction materials used at the site.

Among the individuals indicted is Premchai Karnasuta, one of Thailand's top tycoons.

He serves as executive director of the Italian-Thai Development (ITD) company -- one of the kingdom's biggest construction businesses, which has also been indicted.

If convicted, 71-year-old Premchai faces up to 10 years in prison and a fine of 200,000 baht ($6,000).

This is not the tycoon's first legal tangle.

In 2021, a Thai court sentenced him to three years and two months in prison for poaching protected wildlife, including a black panther.

He was released early in 2023 as part of a group of inmates granted clemency for good behaviour.

According to public filings with the Stock Exchange of Thailand, Premchai owns nearly 12 percent of ITD's shares.

He was taken into pre-trial detention in May.