Her lawyers told the court at 09:37 local time that Yingluck is presently unwell and could not attend the hearing. 'We don't think the defendant is ill, we think the defendant is hiding ... or has fled, ' a court statement read.
She had been due in court on Friday to hear the verdict but failed to appear, prompting the Supreme Court to issue an arrest warrant.
Sources close to Yingluck told Khaosod that she left Thursday for Singapore where her brother, himself a fugitive former prime minister, was waiting.
The head of Thailand's immigration police chief, Nanthathorn Prousoontorn, said he believed Yingluck still remained in the country. "Will she still say that she didn't get justice?"
"I just learned that she did not show up [at court]", Prayut Chan-O-Cha told reporters.
"In the past one to two days I have not had direct contact with Yingluck but have contacted her team", he said. Ms Yingluck's billionaire brother, Thaksin Shinawatra, who was prime minister between 2001 and 2006, escaped nine years ago before the conclusion of a graft case.
Thaksin, who has lived in Dubai since fleeing a corruption conviction he says was politically motivated, has studiously avoided commenting on his sister's case, apparently to avoid imperiling it.
The Shinawatra family remains popular with many of Thailand's rural poor, but is hated by numerous royalist and military elite in Bangkok.
Her campaigning strategy - dubbed fighting with smiles - and her propensity to shed tears in public forged an image far removed from that of the stern junta generals who ousted her from office in a 2014 coup.
"I think it is clear enough that politics is involved in the Yingluck trial", said Thitinan Pongsudhirak, director of the Institute of Security and International Studies at Bangkok's Chulalongkorn University. Yingluck posted a message on her Facebook page urging followers to stay away, saying she anxious about their safety.
Prawit Pongkunnut is a rice farmer from the northeastern city of Nakhon Ratchasima.
However, it is a poorly-concealed secret that some in the military government would have been happy to see her leave the country before the verdict. Yingluck was also criticized for buying loyalty from her supporters through populism during her premiership without seriously addressing critical hurdles in democratization. Despite the negligence charges, Yingluck remains very popular with many Thai people.
The prosecution has argued that subsidies inflated rice prices, reducing Thailand's competitiveness, hurting the country's export industry. He said he came to the capital last night with 10 other farmers to show solidarity with Yingluck. If convicted, Yingluck has the right to appeal.
Yingluck already has been held responsible for about $1 billion of the losses in an administrative ruling that froze her bank accounts. Threats of arrest and thousands of police had failed to keep them from the Supreme Court as they waited patiently on pavements and plastic chairs. As Bangkok Post reports, former commerce minister Boonsong Teriyapirom was sentenced to 42 years in jail; his former deputy, Poom Sarapol, got 36 years.