Mr Surayud, a former army chief, was installed after a military coup against then premier Thaksin in 2006.

The Asset Examination Committee (AEC), which was set up by the army after the putsch, said Mr Surayud had been called to testify about Thaksin on March 24.

'General Surayud will testify as a witness on matters related to Thaksin's assets and Manchester City,' AEC spokesman Sak Korsaengruang said, declining to say exactly what Surayud would be asked.

Mr Thaksin, a self-made billionaire, lived in self-imposed exile after the coup, staying mainly in Britain. The AEC froze about two billion dollars worth of his assets pending the outcome of corruption investigations.

Despite the freeze, he last year bought the Premier League club for about 163 million dollars.

Mr Thaksin returned to Thailand for the first time since the coup on February 28, when he was welcomed by adoring crowds.

He appeared before the Supreme Court to plead not guilty to corruption charges brought by the AEC over a real estate deal, but last week was granted permission from the court to travel to Britain.

Mr Thaksin told the judges he needed to leave the country to deal with the football club.

The real estate case is the only charge against Mr Thaksin that has made it to court. He is accused of using his political influence to win his wife a bargain price on prime Bangkok property. -- AFP