"The allegations are made up. They are made to justify the coup."
Later, in a news conference in a Bangkok hotel, he apologised to Thai people for the months of the chaos since the coup and said democracy had now returned to Thailand.
"I have to come back to restore my reputation and fight for justice in court," he said.
Shortly after landing, Thaksin surrendered to police before being swept through the airport terminal and kissing the ground in front of the media and thousands of cheering supporters.
Appearing before the Supreme Court less than an hour after landing, Thaksin was formally presented with the corruption charges against him and granted bail of $267,000.
"When the game is over, we must come together and settle our differences, forgive everything and help each other push the country forward"
He was told he could not leave the country without the court's permission.
Al Jazeera's Hannah Belcher who was at the court said unprecedented security had been put in place for Thaksin's appearance.
He was then taken under police escort to Thailand's department of special investigations where he faces separate charges of concealing ownership of shares in a family business.
Show of support
Thousands of supporters had been bussed in to welcome Thaksin's return at the airport and in central Bangkok.
Many had gathered since before dawn, dancing, beating drums, singing and carrying signs that read "We love Thaksin" and "Welcome home".
Thaksin has vowed to fight the charges against him and seek the release of hundreds of millions of dollars in frozen assets seized after the military coup.
|Hundreds of supporters were bussed in from |
across Thailand to welcome Thaksin back
Speaking to reporters ahead of his arrival in Bangkok he had expressed confidence in seeing justice through the Thai court system.
"Normally in justice systems everywhere, a person is innocent until proved guilty," he said.
Nonetheless, he said he had no plans to pursue revenge against those who forced him from power.
"When the game is over, we must come together and settle our differences, forgive everything and help each other push the country forward," he said.
The self-made billionaire-politician and his wife, Pojaman, each face up to 13 years in jail over two corruption charges alleging she used her husband's political influence to buy prime Bangkok property from a government agency at about one third of its estimated value.
Thaksin denies any abuse of power.
The two also face separate charges of making fraudulent filings with the Securities and Exchange Commission over the 2003 listing of a property company.
Thaksin's opponents say his return is no surprise, coming soon after his political allies in the People Power party (PPP) formed the government after wining the general elections in December.
Critics say his return could re-ignite deep political divisions that led to his downfall.
|Thaksin kissed the ground after returning |
from 17 months in exile
Thaksin himself has repeatedly denied that he has any plans to return to politics, telling reporters on the flight to Bangkok that his political career was "finished".
Critics and supporters alike say such claims carry little weight and many believe he intends to run the country from behind the scenes.
Just hours after Thaksin returned to Thai soil, Surapong Suebwonglee, the country's finance minister, told reporters that although the former prime minister was legally banned from all political activity for five years, the government would consult the former prime minister for economic advice.
"We can't appoint him to any official position, but we'll ask him for advice on the economy," Surapong said.
Chamlong Srimuang, a former Bangkok governor, said Thaksin's pledge to stay out of politics was a "political game", and that he had continued playing an important role in Thai politics while in exile.
"Thaksin will plunge the country into a greater crisis that people will not be able to tolerate any longer," the one-time Thaksin ally said.
Thaksin's opponents have also threatened to mobilise protesters and stage demonstrations if the new government tries to intervene in the legal process against him.
On Wednesday, the country's newly-elected prime minister, Samak Sundaravej, who heads the PPP which is regarded as Thaksin's proxy, said he was happy to welcome the former premier back and gave assurances that he would be given a fair trial.
Thaksin's party, Thai Rak Thai, was outlawed after the bloodless military coup in September 2006, and he has been banned from politics for five years.