Yingluck had faced up to 10 years in prison for her role in the rice-buying scheme, introduced in 2011, which pledged to pay farmers well above the market rate for their crops.
Yingluck's administration was toppled in a 2014 coup and she was later put on trial for negligence over her government's rice subsidy scheme, which is said to have cost the country billions of dollars.
Thai Prime Minister Prayut Chan-o-cha said on Thursday former Prime Minister Yingluck Shinawatra is now in the United Arab Emirates.
On Wednesday, Yingluck was convicted in absentia of dereliction of duty for implementing a rice subsidy policy and sentenced to five years imprisonment.
Yingluck, 50, made a dramatic disappearance despite being heavily monitored and was a no-show at her August 25 ruling for corruption charges.
She maintained her innocence throughout the case, which she said was a political fit-up sculpted by her family's enemies among the arch-royalist army and elite.
The search followed testimony by Police-Colonel Chairit Anurit, who last week said he had driven Yingluck from Bangkok to Sa Kaeo province.
Once a fresh arrest warrant is issued, Thai authorities may proceed with extradition efforts, he told reporters.
The pair were among the three police officers suspected of escorting Yingluck on her way out of the country.
He fled Thailand in 2008 to avoid jail on a graft conviction he says was politically motivated.
Pol Gen Srivara said that Pol Col Chairit had not faced a charge, pending the examination of DNA evidence collected from the Toyota auto and the former prime minister's house on Soi Yothin Pattana 3 in Bangkok.
"Although don't have extradition treaty..."
Officials in Dubai did not respond to questions Thursday about Yingluck's whereabouts. The offence is punishable by a jail term of up to five years and/or a fine equivalent to four times the engine's price, Pol Gen Srivara said.
For more than a decade, Thai politics has been dominated by the power struggle between the Shinawatras and Thailand's establishment, which includes the armed forces and urban middle class.
Police examine the Toyota Camry vehicle at the Royal Thai Police headquarters in Bangkok on Sept 22.
Around a dozen police from the forensics unit entered the large compound carrying gloves and metal boxes, to be met by a lawyer for Yingluck and one of her bodyguards.