Mr Thaksin, a billionaire telecoms tycoon who turned to politics, has said he wants to promote Thai football and employ Liverpool coaches to lift the national game to international standards.
Some commentators have said he may be trying to boost his political popularity in the soccer-mad nation.
Mr Thaksin told the BBC: "In principle they agreed to give it to us and now we are working on details." Spokesman Santiparb Tejavanija said: "I am flying to Liverpool tonight. Our proposal has been approved." Mr Santiparb-whose Sports Authority of Thailand (SAT) was appointed by Mr Thaksin to work on the details of the investment, added: "What I will sign in England would be something of a memorandum of understanding or letter of intent.
"After that we will work on the legal details of the investment."
Thailand's bad human rights record has prompted criticism of Liverpool's willingness to do business with Mr Thaksin.
However, the deal would provide a financial boost for the club, allowing them to compete with the Premiership's richest clubs, buy new players, and help finance an £80million proposed new stadium in Stanley Park.
Shinawatra - whose regime has been criticised by Amnesty International - declared a "war on drugs" last year and 2,245 suspected dealers died within three months. Officials said police had shot around 40 in self-defence while the rest died at the hands of rival gangs.
