US Congress has been questioning whether Russian money could have been used to fund Donald Trump's golf courses in the UK and Ireland.
It emerged after the permanent select committee on intelligence at the US House of Representatives released a transcript of the sworn testimony of former Wall Street Journal reporter Glenn Simpson.
Mr Simpson, who works for consulting firm Fusion GPS, was asked to research then presidential candidate Donald Trump in 2015/16.
He told the committee that he looked at the Trump golf courses in Scotland and Ireland as part of his research.
Asked whether he saw Russian money involved with them he replied: "Well, we had - you know, we saw what Eric Trump said about Russian money being available for his golf - for the golf course projects, making remarks about having unlimited sums available.
"And, you know, because Mr Trump's companies are generally not publicly traded and don't do a lot of public disclosure, we can only look - have a limited look into the financing of those projects.
"But because the Irish courses and the Scottish courses are under UK, you know, Anglo corporate law, they have - they file financial statements.
"So we were able to get the financial statements. And they don't, on their face, show Russian involvement, 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.
"And these golf courses are just, you know, they're sinks. They don't actually make any money.
"So, you know, if you're familiar with Donald Trump's finances and the litigation over whether he's really a billionaire, you know, there's good reason to believe he doesn't have enough money to do this and that he would have had to have outside financial support for these things."
Mr Simpson said that he is mostly working off public records.
He said: "A lot of what I do is analyse whether things make sense and whether they can be explained.
"And that didn't make sense to me, doesn't make sense to me to this day."
The Trump golf resorts in Scotland are at Turnberry in Ayrshire and the Menie Estate in Aberdeenshire, while in Ireland there is Trump Doonbeg.
Donald Trump resigned as director of the family's Scottish and Irish golf courses just before his inauguration as president in January last year.