The wife of deposed Prime Minister Thaksin Shinawatra said Wednesday that her husband will return home from self-imposed exile in May to face corruption charges.

Pojamarn Shinawatra made the statement when appearing before the Supreme Court on charges that she used her husband's political influence to buy prime Bangkok real state from a government agency at a third of its estimated value.

During the brief first hearing, Pojamarn pleaded not guilty and asked the court for 90 days to prepare documents and witnesses to buttress her defense. The court set the next hearing for April 29.

Pojamarn returned to Thailand earlier this month in a trip Thaksin said was to prove their innocence and clear the family's name. He was toppled in a bloodless military coup in 2006, with opponents accusing him of massive corruption and abuse of power.

Thaksin, who resides mostly in London, has given several different dates for his return home. Most recently he said he was "considering" a comeback in April.

Pojamarn's return and Thaksin's potential return have added tension to Thailand's unsettled political situation, in which Thaksin's followers have formed a coalition government following their victory in general elections last month.

Pro-Thaksin stalwart Samak Sundaravej is expected to be named prime minister Friday amid opposition from the military and anti-Thaksin activists who led mass demonstrations prior to the coup.

Thaksin has vowed to stay out of politics but said he is ready to serve as an adviser to his allies in the People's Power Party, which Samak heads.

Pojamarn, Thailand's first lady in 2001-2006, flew back to Bangkok on Jan. 8. She was later served two arrest warrants and released on $202,000 bail.

If convicted in both cases, Pojamarn and Thaksin could face a total of up to 28 years behind bars.

It will be a landmark trial after months of investigations into Thaksin and his family's alleged corruption. The second arrest warrant alleges that the Shinawatras concealed millions of dollars in stock market shares. A trial date has not been set for that case.

Pojamarn is formally charged with conflict of interest and malfeasance in the 2003 purchase of a 1-acre plot of land in central Bangkok from the Financial Institutions Development Fund, a government agency set up to bail out debt-ridden banks.

She paid $26 million for the land, which was worth triple the amount.

An anti-corruption law bars prime ministers or their spouses from doing business with government agencies.