Thailand's former Prime Minister Thaksin Shinawatra will be indicted on charges of insulting the monarchy, the country’s attorney-general has said.

The controversial political leader, who returned to Thailand last year after 15 years in exile, is being charged over an interview he gave to a Korean newspaper nine years ago.

He is the most high-profile figure to face charges under Thailand's notorious lese majeste law, which has been used extensively against political dissidents.

Hundreds of people have been charged in the last four years alone.

A huge figure in Thai politics, Mr Thaksin's return to the country last year had appeared to put an end to the bitter political rivalry between his family and the conservative groups who feared his populist style of leadership.

In what had looked like a grand bargain, his party was allowed to form a coalition government with some of his political opponents, to keep out the youthful reformist party Move Forward which had won the most votes and seats in the 2023 election.

But the decision to indict the 74-year-old former premier under the draconian lese majeste law shows that he still has enemies in Thailand’s powerful royalist establishment.

The charges related to an interview he gave to a Korean newspaper in 2015 while he was in exile.

In that article, he had accused the king’s top advisory body, the privy council, of helping engineer the 2014 military coup which deposed an administration led by his sister Yingluck.

Yingluck Shinawatra, elected in the 2011 general election, led Thailand for three years before being ousted by the coup.

The privy council is not technically covered by the lese majeste law, but these days it has been often broadly interpreted to cover any opinion which might reflect negatively on the royal family.

More than 270 people have been charged under the law since mass protests four years ago in which the monarchy was subjected to unprecedented public criticism.

Mr. Thaksin’s lawyers say they are confident of defending him in court; but in the typically protracted period before he is likely to go to trial this indictment may force him to limit his political ambitions.