TEHRAN, Young Journalists Club (YJC) - Yingluck on Friday failed to show up at court in a case centered on the multi-billion dollar losses incurred by a rice subsidy scheme for farmers, for which she faced up to 10 years in prison if found guilty.
"She has definitely left Thailand," a member of the Shinawatra's Puea Thai Party told Reuters, without saying where she is now.
Yingluck reportedly said she could not attend the court hearing because of an ear problem, after which the Supreme Court issued an arrest warrant.
"We don't think that the defendant is ill. We think that the defendant is hiding or has fled ... We have pushed back the verdict date to September 27," a statement from a Supreme Court judge said.
Junta chief ordered border checkpoints to be beefed up after Yingluck failed to turn up at the court that could have seen her jailed.
Prayut Chan-O-Cha told reporters that he had ordered border checkpoints, including local and major routes out of the country, to be stepped up.
Deputy Prime Minister Prawit Wongsuwan earlier said it was possible the ousted prime minister had fled the country. "It is possible that she has fled already," Prawit told reporters as he left a meeting in Bangkok.
Yingluck’s supporters gathered outside the Supreme Court building in the capital.
Bangkok's metropolitan police said around 4,000 police were deployed at the court and checkpoints had been set up.
A rice subsidy program - a flagship policy of Yingluck's administration - saw her government buy farmers' crops at prices up to 50 percent higher than market prices.
The policy was popular with farmers but left Thailand with huge rice stockpiles and caused at least $8 billion in losses.
Yingluck has defended the rice plan saying it benefited the farmers and pleaded not guilty to the negligence charges. She has said she was only in charge of coming up with the policy, but not the day-to-day implementation of the plan, Presstv reported.
Yingluck became Thailand's first female prime minister in 2011. The youngest sister of tycoon and former prime minister Thaksin Shinawatra was impeached in 2015 over the rice scheme by a military-backed legislature.