Fugitive sibling former prime ministers, Thaksin Shinawatra and Yingluck Shinawatra, have left China and are bound for Japan, according to deputy premier Prawit Wongsuwon.
Gen Prawit's remarks came after a photo of the pair emerged online on Saturday with reports suggesting they were in Beijing.
The deputy premier said relevant agencies will work on bringing them to justice. He said the two former premiers were heading for Japan after China.
Prime Minister Prayut Chan-o-cha, meanwhile, shrugged off speculation the pair's presence in China could create political instability in Thailand.
"I have no opinion about that. This is a matter of a foreign country and relevant agencies which are keeping track of them," said Gen Prayut.
Asked whether it is coincidental that the photo emerged when an anti-coup protest was being staged at the same time at the Democracy Monument on Saturday, the prime minister said: "I don't take any interest in it. Do not pay attention to it. Why are you interested in people who break the law?"
Meanwhile, Foreign Minister Don Pramudwinai said he was informed that Yingluck was in Beijing.
Her Thai passports were cancelled, but Ms Yingluck may have obtained a passport from another country in exchange for investing in it.
He said the ministry had notified various countries about Yingluck's fugitive status.
Forensic officials were also ordered to examine whether the photo of Thaksin and Yingluck was genuine, Pol Gen Srivara said.
