There was no conflict between former prime minister Thaksin Shinawatra and US attorney Robert Amsterdam that caused the two to part ways, says Thaksin's local legal adviser Noppadon Pattama.
Mr Noppadon said Mr Amsterdam's departure is nothing out of the ordinary. His employment contract to defend the rights of those in the red-shirt pro-democracy movement has expired, and there was not enough work now to keep Mr Amsterdam occupied.
Amsterdam: Now targets coup-makers
"Mr Amsterdam has never been Thaksin's lawyer. In fact, Mr Thaksin hired him to act for the UDD (the red-shirt United Front for Democracy against Dictatorship)," said Mr Noppadon.
The firm Amsterdam & Partners LLP was first retained in April 2010 to handle high-profile red shirt cases, including a petition to the International Criminal Court following the dispersal of red-shirt protesters in Bangkok that resulted in more than 90 deaths.
"However, following the military coup on May 22 last year, conditions for human rights have sharply deteriorated, and the engagement between Robert Amsterdam and former prime minister Thaksin has now concluded," the firm said.
Mr Amsterdam has also launched an independent campaign to hold Thailand's coup-leaders accountable in foreign jurisdictions, the firm said.
The movement hopes to bring criminal charges against the coup-leaders and those responsible for the 2010 Bangkok massacre, as well as delivering justice for the victims.
Meanwhile, Panitan Wattanayagorn, adviser to the deputy prime minister for security affairs, said yesterday that a criminal exchange treaty should be considered to bring lese majeste suspects who have fled overseas back to Thailand to face their charges. The treaty could also cover fugitives such as Thaksin.
However, he said Thai authorities would have to do more to promote understanding about lese majeste with foreign governments, admitting that such governments may be unwilling to help, given the current political situation.
Thailand needs to explain that suspects are criminals, not political exiles, he said.