Mr Thaksin has lived in exile since the September 2006 coup
Former Thai PM Thaksin Shinawatra will be arrested if he returns to the country, officials have warned.
“The police have to comply with arrest warrants which have already been issued by the courts,” said Samphan Sarathana, of the attorney-general’s office.
Mr Thaksin, who was forced from power by a military coup more than a year ago, said on Tuesday he was considering returning home from exile.
He said he wanted to prove himself innocent of corruption charges.
The party he backed emerged from weekend general elections with the largest number of seats in parliament.
But Mr Samphan, a director-general in the attorney-general’s office, said the results of the election had no bearing on the legal cases against the former prime minister.
“The case has gone too far for a reversal,” he said.
At Tuesday’s news conference, Mr Thaksin said he would start “exploring options” for a return to Thailand as early as mid-February.
September 2006: Coup overthrows Thaksin Shinawatra
October 2006: Retired General Surayud Chulanont is appointed interim leader
May 2007: Court bans Mr Thaksin from politics for five years, and dissolves his party
August 2007: Voters approve a new constitution
December 2007: Election held
But he insisted that he did not want to make a return to politics.
He did however say he would be willing to act as a political adviser to the People Power Party (PPP) – made up of his supporters and political allies – if asked.
“If they want my opinion and ideas, then I will give it to them,” Mr Thaksin said.
“I really want to go back as a normal citizen. Enough is enough for politics,” he added.
Mr Thaksin, the owner of Manchester City football club, has resided in the UK since being forced from power.
Since the coup, the country has been ruled by a military-appointed interim administration.
In May the courts banned Mr Thaksin from taking part in politics for five years and dissolved his party, Thai Rak Thai.
But many of Thai Rak Thai’s members decided to continue in politics, and formed the PPP.
PPP leader Samak Sundaravej has openly said that he is a proxy for Mr Thaksin and will bring the former prime minister back to Thailand if he takes office.
Analysts say the success of the PPP shows that the public has rejected the coup and continues to support Mr Thaksin, particularly in rural areas.