The House Intelligence Committee on Thursday posted the transcript of its November interview with Glenn Simpson, the co-founder of the research firm Fusion GPS, which was responsible for the dossier on Donald Trump and Russian Federation.
"And these golf courses are just, you know, they're sinks".
Mr Simpson, who works for consulting firm Fusion GPS, was asked to research then presidential candidate Donald Trump in 2015/16.
US Congress has been asking questions about Donald Trump's funding of his Irish golf course - and whether it could have been financed with Russian mafia money.
"They don't, on their face, show Russian involvement", he replied, "but what they do show is enormous amounts of capital flowing into these projects from unknown sources and - or at least on paper it says it's from The Trump Organisation - but it's hundreds of millions of dollars".
But during the testimony, Republicans questioned whether the allegations Simpson was making actually had evidence to back them up.
At various points, Simpson advises the committee on how to direct its investigation and outlined what he said were connections between the Trump orbit and Russian Federation.
"So the first thing that I would do would be to subpoena the brokers and the people, the other people that were involved in the transactions, and the title companies and the.other intermediaries that would have that kind of information", Simpson said, when asked specifically about how the committee should go about the investigating the money laundering allegations. "And that didn't make sense to me, doesn't make sense to me to this day".More news: Israeli military storms West Bank's Jenin, kills Palestinian
His testimony generated interest from House committee member, Tom Rooney, a Republican congressman from Florida.
The Trump golf resorts in Scotland are at Turnberry in Ayrshire and the Menie Estate in Aberdeenshire, while in Ireland there is Trump Doonbeg.
Recently released testimony shows Fusion GPS founder was trying to steer the FBI away from further investigation of the Clintons while he was encouraging investigators to look into Trump. "It was - he was - you know, it was viewed as reporting a crime in progress, sort of a citizenship obligation", Simpson said.
Donald Trump had links to the Russian mafia during his time as a real estate developer, according to the founder of the company behind the infamous dossier alleging ties between the president and Russia.
"So, I mean, that's why it's so fascinating".
Mr Trump's Irish golf course has yet to turn a profit.
Donald Trump resigned as director of the family's Scottish and Irish golf courses just before his inauguration as president in January past year.
Mr Trump bought the resort of nearly €9 million in 2014, the year before he announced his candidacy for the U.S. presidency, and promised to invest €45 million in the business.
The committee released a transcript of the hours-long interview on Thursday, following the lead of a separate Senate panel that made public its own session with Simpson.