Prime Minister Prayut Chan-o-cha says various agencies are considering legal action against Pannika Wanich, spokeswoman of the freshly dissolved Future Forward Party (FFP), over her allegation that the government and state agencies helped cover up Malaysia's multibillion-dollar 1MDB scandal.
Gen Prayut yesterday warned Ms Pannika to be careful since her claim about Malaysia's defrauded state development fund could hurt relations between the two countries.
He also warned she could face legal action since she is no longer an MP and thus is not protected by parliamentary immunity.
Ms Pannika was among 16 FFP executives stripped of their MP status and banned from politics for 10 years when the party was dissolved by the Constitutional Court over a controversial loan last Friday.
Government spokeswoman Narumon Pinyosinwat dismissed Ms Pannika's allegation on Facebook yesterday.
She said relevant agencies were considering taking legal action over the matter.
Pol Gen Chakthip Chaijinda, the national police chief, said the force's legal office will examine a recording of Ms Pannika's allegation, made on Sunday ahead of a debate against the government outside parliament at the FFP's Thon Buri office.
Deputy Prime Minister Prawit Wongsuwon strongly denied the accusation.
"We can't stop her speaking. I don't know where or how she got that information," he said, declining to comment further when asked if it came from the Immigration Bureau.
Meanwhile, deputy police spokesman Kissana Phattanacharoen dismissed Ms Pannika's claim that Thailand had jailed an innocent person, Xavier Andre Justo, a Swiss national involved in exposing the 1MDB scandal.
Pol Col Kissana said that Justo pleaded guilty, after which his six-year sentence was cut in half.
Justo was arrested on Koh Samui in Surat Thani province in June 2015.
The Southern Bangkok Criminal Court convicted and sentenced him to a commuted three-year jail term in August 2015 for attempting to blackmail his former employer, PetroSaudi International, by threatening to sell confidential documents related to the company's transactions with Malaysia's 1MDB unless the company paid him US$2.5 million.
Justo was released from prison under a royal pardon in Dec 2016.