Facing a possible 10-year jail term, former Thai Prime Minister Yingluck Shinawatra fled the country before a court verdict her supporters say was politically motivated, local media and officials said.
Yingluck's whereabouts were not immediately known on Saturday.
However, anonymous officials told Reuters news agency that she travelled by land to Cambodia then flew to Dubai to join her brother, Thaksin Shinawatra - another exiled former premier whose government, like hers, was toppled in a military coup.
An official of Yingluck's Pheu Thai party close to the Shinawatra family, meanwhile, told The Associated Press she was no longer in Thailand, without giving further details.
Yingluck, who became Thailand's first female prime minister when her party swept elections in 2011, is accused of negligence in overseeing a money-losing rice subsidy programme. She has denied charges as politically motivated.
A verdict had been expected on Friday, as thousands of Yingluck supporters gathered outside the court and thousands of police stood guard.
But Yingluck never appeared.
A judge read out a statement saying her lawyers had informed the court she could not attend because of an earache.
The judge said the court did not believe the excuse, however, because no official medical verification was provided. He said a warrant would be issued for her arrest and postponed the trial until September 27.
Norrawit Larlaeng, Yingluck's lawyer, confirmed a warrant had been issued, but said he had no details on her whereabouts.
Prime Minister Prayuth Chan-ocha, the military chief who engineered the 2014 overthrow of Yingluck's government, also said he did not know where she was, and the government was "looking for her".
"If she's not guilty she should stay and fight the case," Prayuth said. "If she's not here, what does that tell you? Will she still say that she didn't get justice?"
The long-awaited decision on Yingluck's fate has rekindled tensions in the divided nation, but the military remains firmly in charge.
The rice subsidies, promised to farmers during the 2011 election, helped Yingluck's party ascend to power. Critics say they were effectively a means of vote-buying, while Yingluck supporters welcomed them.
The rice subsidy plan Yingluck oversaw paid farmers about 50 percent more than they would have made on the world market.
The hope was to drive up prices by stockpiling the grain, but other Asian producers filled the void instead, knocking Thailand from its perch as the world's leading rice exporter.
The current government, which is still trying to sell off the rice stockpiles, says Yingluck's administration lost as much as $17bn because it could not export at a price commensurate with what it had paid farmers.
If convicted, Yingluck has the right to appeal.