Missing former Thai premier Yingluck Shinwatra will address the public when the time is right, her Puea Thai party said in a statement on Tuesday (Aug 29).

In the meantime, the party will continue its fight for "true democracy" and economic prosperity.

"At the appropriate time, Puea Thai Party believes that former prime minister Yingluck Shinawatra, who is a valuable resource of the party, will make a public statement," it said, in its first official comments since the embattled former leader failed to turn up in court on Friday (Aug 25) to hear the verdict in a criminal negligence case that could have landed her in jail for up to 10 years.

"Puea Thai Party believes that we will continue to be a political party for the people, creating stability and opportunities for the people without any inhibitions," it said.

The statement comes amid intense speculation over the whereabouts of Ms Yingluck, who stumped hundreds of supporters and even fellow party members with her no-show on Friday.

Public prosecutors had alleged that she, as prime minister, had mismanaged the multi-billion dollar programme that paid rice farmers some 50 per cent above market prices for their paddy.

The court has issued an arrest warrant for her and postponed its verdict reading to Sept 27.

The rice subsidy scheme was a key campaign promise of the Puea Thai party, which won a landslide victory in the 2011 elections. But it left state warehouses overflowing with paddy, and unseated the Kingdom as the world's top rice exporter.

"All the serious obstructions and challenges we are currently facing will empower the party, members and supporters to love and understand on another, and be even stronger in our commitment towards the betterment of Thai society with peace and economic prosperity for the people," Puea Thai said.

Yingluck, Thailand's first female prime minister, was ousted by a court ruling in 2014 shortly before the rest of her government was topped by a military coup. She was retroactively impeached in 2015, and had her assets seized as the military government tried to fine her some 35 billion baht for the rice scheme.

She is now said to be in Dubai, where her brother Thaksin Shinawatra - another former prime minister ousted by a coup - lives in exile.

The ruling junta, which kept her under tight surveillance in recent years, has denied allegations that it had helped Yingluck leave the country. Her imprisonment would have created a powerful martyr figure, and heightened political tensions in the divided Kingdom.

But army chief Chalermchai Sitthisat defended state surveillance strategies on Tuesday.

"As of now, we learnt that she abandoned all of her phones and changed her cars so it was hard to trace her using the same methods we did before," he was quoted by Reuters as saying.

Officers who used to guard the front of her home in Bangkok had also been withdrawn.

"The public alleged that it was violating her personal rights and intimidating her so we withdrew the force," he said.

General Chalermchai said it was unlikely Yingluck flew directly out of Thailand, given the security procedures at airports. She might have instead left the country by land or sea instead, and then taken a private flight organised by Thaksin.

Thailand's government has no immediate plans to revoke Yingluck's passports. She holds one regular and one diplomatic Thai passport.

But the Thai police they will seek cooperation from Interpol to track Yingluck down, according to The Nation.