BANGKOK (Reuters) - Former Thai Prime Minister Thaksin Shinawatra said on Saturday he was ready to face charges of insulting the monarchy that mark a setback to a political heavyweight whose allies are currently in government.

The complaint, lodged by the royalist military that ousted the government of his sister Yingluck Shinawatra, stems from an interview the influential tycoon gave to foreign media in 2015. Other charges include violating a computer crime law.

Thaksin said he would meet prosecutors on June 18, but he was not concerned about the case and was ready to fight it.

"It's nothing. The case is baseless," he told reporters.

Thaksin, 74, denies wrongdoing and has repeatedly pledged loyalty to the crown, criticism of which is forbidden under Thailand's controversial lese-majeste law, one of the strictest of its kind around the world.

His is the most high-profile case among more than 270 prosecutions in recent years under the law, which carries a maximum jail term of 15 years for each perceived insult against the royal family.

Thaksin founded the populist Pheu Thai party and his family's parties have won all but one election since 2001, with three Shinawatra governments toppled by coups or court rulings.

The billionaire returned to Thailand in 2023 from 15 years of self-imposed exile, when he remained a central figure during repeated bouts of political upheaval.

He was convicted of abuse of power and conflicts of interest and sentenced to eight years in prison, later commuted to one year by the king. He was released on parole in February after just six months in detention.

Pheu Thai leads the current government, with Thaksin's business ally Srettha Thavisin serving as prime minister and his daughter, Paetongtarn Shinawatra, the party's chief.

(Reporting by Panarat Thepgumpanat Writing by Orathai Sriring; Editing by Helen Popper)