Authorities have launched a lese majeste probe against former prime minister Thaksin Shinawatra after the Foreign Ministry announced Wednesday that it has revoked his two Thai passports.
The move was seen as a response to Thaksin's interview in Seoul last Wednesday with Chosun Ilbo, when he claimed privy councillors supported the May 22 coup last year that ousted his sister Yingluck's government.
A clip of the interview was spread and viewed widely on Thai social media.
Police believe the interview could violate the lese majeste law, as well as other criminal and computer-crime laws.
A statement released by the Foreign Ministry says that security authorities believe parts of Thaksin's interview undermine "national security and dignity".
Police are investigating the case and preparing for criminal action against him under sections 112, 326 and 328 of the Criminal Code and Section 14 (3) (5) of the Computer Crime Act, it said.
As a result, the ministry revoked Thaksin's two Thai passports, as of Tuesday.
Section 112 of the Criminal Code is known as the lese majeste law, for which violators can be jailed for between three to 15 years.
Sections 326 and 328 involve defamation, with imprisonment not exceeding two years and a fine of up to 20,000 baht. The Computer Crime Act's Section 14 involves importing and disseminating computer data involving the previous offences. The penalty is imprisonment for up to five years.
National police spokesman Prawut Thawornsiri said security agencies lodged a complaint with the Crime Suppression Division, seeking legal action against Thaksin, after learning that his recent interview contained messages deemed to violate Thai law on several counts.
Pol Col Olarn Sukkasem, a superintendent of the Technology Crime Suppression Division of the Central Investigation Bureau, was appointed as lead investigator on a panel recently formed to assess Thaksin's speech in light of the laws.
Norachit Singhasenee, permanent secretary for foreign affairs, explained it was not unusual that Thaksin had two Thai passports, as every citizen is entitled to apply for two.
For example, business people who travel frequently may need two passports to apply for several visas at the same time, as each application can take weeks, he said.
Thaksin also holds passports from Montenegro and Nicaragua, according to Foreign Ministry spokesman Sek Wannamethee.
In 2008, he was sentenced in absentia to two years in jail by the Supreme Court's Division for Political Office-Holders for abuse of power after selling state land to his then-wife when he was prime minister. He fled Thailand before being sentenced and has since lived in self-exile abroad.
After the 2007 coup, Thaksin's passports were revoked, but Ms Yingluck reinstated his travel documents in 2011 under her administration.
The Abhisit Vejjajiva administration had justified revoking Thaksin's passports under the claim that Thaksin had incurred damage to Thailand, said former foreign minister Surapong Tovichakchaikul, who worked in the Yingluck administration and was responsible for getting Thaksin his passports back.
He said the foreign minister has the authority to decide to revoke or reinstate passports, and he chose to give Thaksin's back because he did not believe Thaksin damaged Thailand.
"And if I return to power [as foreign minister], I will give [him] back his passports again," said Mr Surapong.
Jaran Ditapichai, a red-shirt who lives in exile abroad because of lese-majeste charges brought against him after the coup, said such passport revocations violate citizens' rights and freedom of travel.
Mr Jaran's passport was revoked last July.
Deputy government spokesman Weerachon Sukhonthapatiphak said the decision to revoke Thaksin's passports were made by the Foreign Ministry, after the police forwarded the allegations to the agency.
Police are responsible for compiling information on people whose passports should be nullified and sending the charges on to the Foreign Ministry to make a decision, Maj Gen Weerachon said.