Former Thai Prime Minister Thaksin Shinawatra has been found guilty of corruption and sentenced to two years in prison in absentia by the country's Supreme Court.
In a landmark ruling on Tuesday, Thaksin was found to have used political influence to help his wife Pojaman purchase land from a state agency at a knock-down price in 2003.
He was cleared of more serious charges of abusing his powers to obtain the deal.
One judge said Thaksin had violated the article of the constitution on conflict of interest, as he was then prime minister and head of government who was supposed to work for the benefit of the public.
Pojaman Shinawatra was cleared of all charges over the land deal. However, she has already been convicted of tax evasion and sentenced to three years' jail.
Thaksin, a telecoms tycoon who became the first Thai prime minister to complete his first term and be re-elected, was ousted in a military coup in September 2006.
The junta claimed there was massive corruption and abuse of power under his rule and set up a corruption investigation unit, which has stacked the charges up against Thaksin and his family.
Thaksin and his wife fled to the United Kingdom in August this year, saying they would not get a fair trial. Thai prosecutors on Tuesday called for Britain to extradite him.
The Supreme Court decision is the first in a series of cases lodged against Thaksin and comes amid growing tension between his supporters and opponents.
For weeks protesters have demanded the resignation of the government, saying it is too close to Thaksin.
The administration of Prime Minister Somchai Wongsawat - who is Thaksin's brother-in-law - has been virtually paralysed by the protests.
The BBC reports the verdict is unlikely to pacify the thousands of protesters who have been camped outside the prime minister's office for the past two months.