The former Thai prime minister, whose team is coached by Sven-Goran Eriksson, was taken into custody by police to face corruption charges after his arrival at Suvarnabhumi International Airport on a Thai Airways flight from Hong Kong.
Two arrest warrants were issued for the 58-year-old, who took over Manchester City last summer, after the September 2006 coup that removed him from power. He denies all charges.
Thaksin was driven to the Supreme Court to face the charges against him.
“I believe in the Thai justice system, especially the court system,” Shinawatra had earlier told reporters before boarding the plane in Hong Kong. “Normally in justice systems everywhere, a person is innocent until proved guilty.”
Members of the Manchester City player squad - reportedly goalkeeper Kasper Schmeichel and midfielder Kelvin Etuhu - were on the flight and said they planned to hold some soccer clinics with Thai children and work out with the national team.