Donald Trump's Scottish golf courses were investigated by the team behind the dossier on the US president's alleged ties to Russia.
The report, published in January last year, included claims Mr Trump's election campaign was supported by Russian head of state Vladimir Putin.
It has now emerged that the finances of Mr Trump's golf courses in Aberdeenshire and South Ayrshire were an early focus of research for the dossier.
The connection was revealed when a US senator leaked a transcript of an interview with the co-founder of the company which produced the report.
The confidential meeting with Glenn Simpson in August last year was part of the official Trump-Russia inquiry.
Mr Simpson, who started Fusion GPS in 2011, told US officials his investigators "did an enormous amount of work" on Mr Trump.
He said: "We were not totally focused on Russia but we were at a point where we were drilling down on specific areas. Scotland was one."
Mr Simpson said the reason for investigating Mr Trump's golf courses was to establish more information about his financial dealings.
"The original inquiry was into the value of the courses, whether he had to borrow money to buy them, whether they were encumbered with debt, how much money they brought in, what valuations he put on them, and property tax filings," he said.
Mr Trump is the first modern US president to withhold his tax returns from public scrutiny but Mr Simpson said the relative openness of the UK's financial system was an asset to their investigation.
"[Mr Trump] has golf courses in Scotland and Ireland and one of the facets of UK company law is that private companies have to file public financial statements," he explained.
"When you're looking at a guy like Donald Trump who doesn't like to share information about his company, it's useful to find a jurisdiction where he's required to share that information.
"So we went and ordered the records - the financial statements of the golf courses."
Mr Simpson claimed Donald Trump's golf courses "are not profitable entities".
"[Mr Trump] sunk a lot of money into them and he hadn't gotten a lot of money back yet," he added.
The president's Scottish golf courses are not mentioned in the final report produced by Fusion GPS and there is no suggestion any wrongdoing or impropriety has taken place in connection with them.
Mr Trump has denied allegations his campaign colluded with Russia and is suing BuzzFeed News, which first published the dossier, for defamation.
The 312-page transcript containing Mr Simpson's testimony was leaked this week by Democratic senator Dianne Feinstein, who claimed she acted at his behest.
Ms Feinstein said she made the decision to release to clear up the "innuendo and misinformation" about Fusion GPS and its motivations.
Former MI6 spy Christopher Steele largely authored the final report published by BuzzFeed News, although it is unclear whether or not he was involved in the investigation into Mr Trump's golf courses.
Research for the dossier reportedly began in September 2015 after Fusion GPS was hired by the Washington Free Beacon, a conservative political website.
The Beacon halted the investigation when Mr Trump emerged as the likely Republican candidate in the 2016 US election in spring that year.
Fusion GPS was then retained by the law firm Perkins Coie to continue its research on Mr Trump on behalf of the campaign to elect Hillary Clinton and the Democratic National Committee.
Mr Steele was hired in June 2016 and produced series of 35-page memos which became the Steele dossier.
STV News has approached the Trump Organisation for comment.