Deputy Finance Minister's wife Ms. Lyubov Chernukhina donated £ 1.7m to the Conservative Party, the files of the Financial Crimes Unit of the US Treasury Department revealed.
Two months before the Brexit referendum Ms Chernukhina transferred more than £ 1.5 million to the accounts of the British Conservative Party.
On April 29, 2016 a Russian firm linked to the businessman and senator close to Kremlin transferred £ 8 million to Ms Chernukhina's husband company registered in British Virgin Islands.
The author of the Deutsche Bank report in New York listed $ 278.5 million payment of the offshore company Definition Services. The investigation revealed that the Russian senator's children control the company. Bank flagged this transaction as suspicious and informed the financial security institutions.
The report is part of the files prepared by the secret Financial Crimes Unit of the US Treasury Department which conducts investigation into the money laundering of Kremlin officials. The media obtained some of these files.
Ms Chernukhina donations to Tories allowed her access the high officials in the British government.
For 135,000 pounds (174,500 dollars), she received an invitation to a ladies' evening in an expensive hotel with members of Ms Theresa May government in April 2019. Ms Chernukhina won the right to play tennis with Prime Minister Boris Johnson twice at an auction.
She paid £ 45,000 for her last match in February, and in 2014 she paid £ 160,000 to play tennis with then Prime Minister David Cameron and then-London Mayor, and high official of the Conservative Party, Mr Boris Johnson.
A representative of the British Electoral Commission stated that the donations were legal.
A spokesman for the Conservative Party commented: There are people of Russian origin in this country who are British citizens and have the democratic right to donate to a political party.
But the fact that the US State Department's financial investigation unit focused on these financial transactions revealed that there was a clear assertion of their criminality.