Chalongphob told journalists on the sidelines of an East Asian economic forum in Singapore that Thaksin, who already faces corruption charges in Bangkok, had declared no overseas assets when he was in power.

The minister said the funding for the 162.6 million-dollar bid for the English Premier League football club was a "mystery" to Thailand.

"I'm sure that the Assets Examination Committee will look at the source of his funds and will try to see whether they are legal funds that were taken out, or other means ...," said the Thai minister.

He said, "it's difficult to trace all these movements" of funds by the former leader, a self-made billionaire who currently lives in London after being ousted by a military coup last September.

A powerful anti-graft panel has frozen 1.52 billion dollars of domestic funds belonging to Thaksin and his family as part of investigations.

Chalongphob repeatedly maintained Sunday that the military-backed government does not interfere in the judicial system and said Thaksin would receive protection if he returned to face charges in Bangkok.

"If he comes back, they will have to provide protection for sure," said the minister, who was attending a meeting of government officials, corporate leaders and experts under the auspices of the World Economic Forum.

If Thaksin is found guilty on criminal charges, he could be extradited to Thailand on the basis of bilateral agreements with some countries, Chalongphob added.

Manchester City accepted Thaksin's takeover bid in London Thursday, hours after Thai prosecutors laid formal criminal corruption charges against the former leader.

The formal bid for the Blues was made by Thaksin's UK Sports Investments company and backed by management at Manchester City.

Although Thaksin has won over the board, he must still gain the backing of other shareholders and pass a standard "fit and proper person" test. This is carried out by the Premier League, which runs the Premiership.