Keith Harris, who brokered Thaksin Shinawatra's takeover of Manchester City, insists the Thai's money is clean.
Thailand authorities are set to investigate the source of the funds behind Thaksin's offer.
"It has been legitimately and transparently transferred to the UK."
Thaksin, who lodged a formal offer for City on 21 June, is facing corruption charges in Thailand over a property deal and has had £830m of his assets frozen.
And Thailand's finance minister Chalongphob Sussangkarn says there is also a 'mystery' over how Thaksin has funded his bid for City.
Harris is adamant the charges facing Thaksin in Thailand will have no bearing on his bid for the Premier League club.
"The charges levelled against him are politically motivated by a military government that is unelected.
"He was the Prime Minister there and was exceptionally popular. He was also a successful businessman.
"A number of bank accounts in Thailand, some personal and some corporate, have been frozen.
"But the money that has been used to finance the takeover and which will then be used to invest in the club is in English bank accounts and beyond their reach."