Thailand's ousted prime minister Yingluck Shinawatra said the military junta that overthrew her has ordered her assets seized and fined her 35 billion baht (814.5 million pounds) over a rice subsidy scheme critics say haemorrhaged billions of dollars.

The scheme, which paid farmers above market rates for their rice, was a flagship policy of Yingluck's administration and helped sweep her to office in a 2011 general election.

After her 2014 overthrow, Yingluck was charged with criminal negligence over the rice subsidy scheme and is now fighting the charges in court.

Yingluck told reporters outside a Bangkok court on Friday that she had received a notice two days ago ordering her assets to be seized.

"In terms of the order, it is not right and it is not just," Yingluck said. "I will use every channel available to fight this."

The rice subsidy scheme was a populist policy engineered by Yingluck's brother, former prime minister Thaksin Shinawatra, who was toppled in a 2006 coup.

Her supporters say the case against Yingluck is part of a military plan to wipe out the influence of the Shinawatra family. The junta denies it is singling Yingluck out.

In addition to cases against Yingluck and senior members of her former cabinet, the junta is investigating some 850 cases related to the rice scheme for graft, government spokesman General Sansern Kaewkamnerd told Reuters.

Many of the cases involve lower ranking public officials and members of the private sector, he said.

An advisor to Yingluck, who declined to be named because of the sensitivity of the matter, told Reuters that the asset seizure was done using section 44 of the interim constitution which gives junta chief Prayuth Chan-ocha, who is also the country's prime minister, absolute power to give any order deemed necessary to "strengthen public unity and harmony".

Yingluck has 45 days to appeal the order.

Analysts said that the seizure of Yingluck's assets was part of a military plan to limit the influence of Yingluck and her brother, Thaksin.

"It is part for the course of the military coup which was to put down the Thaksin challenge once and for all," Thitinan Pongsudhirak, a political science professor at Chulalongkorn University, told Reuters.

The junta said it staged the 2014 coup to bring stability following months of unrest. It denies staging the coup to limit the influence of Thaksin, his family and their political allies.