A senior Democratic senator wants to further investigate a $95million sale of a Florida mansion owned by President Donald Trump to a Russian oligarch 10 years ago, it was reported on Saturday.

Senator Ron Wyden, a Democrat from Oregon, wants the Treasury Department to release documents related to the sale of the six-acre estate in Palm Beach, ABC News reported.

In 2008, Trump sold the mansion for $95million to Dmitry Rybolovlev, a Russian billionaire who made his fortune in mining.

He is perhaps best known as the president of Monaco’s soccer club AS Monaco.

A spokesperson for Rybolovlev told DailyMail.com there was no impropriety in the sale.

'When the Rybolovlev family trust acquired the property in Palm Beach in 2008, it was made very clear that the purchase was an investment,' the spokesperson said.

'The transaction was publicly announced and widely covered by the US media. There was no suggestion whatsoever of any impropriety about the purchase.'

Senator Ron Wyden (above), a Democrat from Oregon, wants the Treasury Department to release documents related to the sale of a six-acre estate in Palm Beach that once belonged to Donald Trump

In 2008, Trump sold the estate in Palm Beach to a Russian billionaire for $95million - more than twice what he paid for it just four years earlier

Trump (left) has insisted there was no wrongdoing in the sale. The property was bought by Russian oligarch Dmitry Rybolovlev (right)

The sale of the mansion has raised suspicions because Trump initially bought the property four years earlier for much less - $41million.

Trump has maintained that he bought the home from the previous owner who declared bankruptcy.

He said that renovations and improvements made to the property boosted its value, enabling him to turn a profit.

‘It is imperative that Congress follow the money and conduct a thorough investigation into any potential money laundering or other illicit financial dealings between the president, his associates, and Russia,’ Wyden, who is on the powerful Senate Intelligence Committee, wrote in a letter to Treasury Secretary Steve Mnuchin.

Trump has maintained that he bought the home from the previous owner who declared bankruptcy

After Rybolovlev bought the property, he tore down the home and subdivided the estate into a number of other properties, which he then sold off

In July, Bloomberg News reported that Robert Mueller, the special counsel investigating alleged Russian meddling in the 2016 elections, was also looking into Russian purchases of Trump real estate properties.

Mueller and his investigators were said to be examining the sale of apartments in a Trump-owned SoHo development in New York as well as the sale of his Palm Beach mansion in 2008.

In 2016, Trump told ABC News that the sale of the home was one of the few times he ever did business directly with a Russian national.

‘The primary thing I did with Russia, I bought a house in Palm Beach at a bankruptcy… I bought it for about $40 million,’ Trump said.

‘I sold it for $100 million to a Russian. And that was primarily it.’

Wyden, who is also a member of the Senate Finance Committee, wrote in the letter that the deal raises questions.

Trump says that renovations done with the home increased its value and enabled him to turn a handsome profit

He purchased the home in 2004 in $41.4 million from nursing home tycoon Abe Gosman. The real estate mogul spent two years renovating the Florida home and then put it back on the market

At the time, it was one of the most expensive home sales every.

Wyden noted that when Trump sold the house, he was having trouble finding a bank that would lend him money.

The sale was also made months before Trump Entertainment Resorts, which owned and operated Atlantic City hotels and casinos, declared bankruptcy.

‘In the context of the President’s then-precarious financial position, I believe that the Palm Beach property sale warrants further scrutiny,’ Wyden wrote.

The Treasury Department logs what are known as ‘Suspicious Activity Reports,’ which keep track of abnormally large transactions that are flagged for possibly involving money laundering.

Wyden wants those records as well as any other documents pertaining to activity done after the sale.

Rybolovlev had the mansion torn down. He then subdivided the estate and sold off slices to other buyers.

Wyden wants to know the identities of the buyers.

Last summer, it was reported that Robert Mueller, the special counsel investigating alleged Russian meddling in the 2016 elections, was also looking into Russian purchases of Trump real estate properties

In years past, individuals would use anonymous shell companies to shield themselves from scrutiny whenever making large purchases of real estate.

But in recent years, the federal government has started requiring title insurance companies in a number of areas, including Palm Beach County, to reveal the names of the individuals behind those companies.

Trump’s lawyer, John Dowd, said last summer that any attempt by Mueller to look into Trump’s financial dealings were ‘well beyond the mandate of special counsel.’

Trump has denied any wrongdoing.

He purchased the home in 2004 in $41.4 million from nursing home tycoon Abe Gosman.

The real estate mogul spent two years renovating the Florida home and then put it back on the market.

The sprawling seven-bedroom home had a garage that could accommodate 80 cars.

The decor included marble floors, bullet-proof windows, mahogany doors, giant skylights and a full-sized ballroom.

Trump enlisted help from realtor Kendra Todd, who had won season three of his NBC show The Apprentice, to help marketing the gigantic property.