Congressional Democrats have formally asked the FBI and US intelligence agencies to investigate the relationship between Donald Trump and Li "Cindy" Yang, who founded and subsequently sold massage parlours implicated in a human trafficking raid last month.

The requested investigation comes as reports have indicated Ms Yang may have started a business that sold access to the president at his Mar-a-Lago resort in Florida.

Ms Yang found herself at the centre of press intrigue after photos of her with Mr Trump at a Super Bowl watch party earlier this year surfaced, followed by other photos showing the Chinese national with the president and members of his family.

The photos provide a connection between the two, and came out after an investigation in Florida that led to a prostitution sting at massage parlours that Ms Yang helped open, but no longer owns.

Among those caught in the prostitution scandal was the owner of the New England Patriots, Robert Kraft, whose team was playing when one of the photos between Ms Yang and Mr Trump were taken. Mr Kraft is known for his support and friendship with the president.

Criminals who worked for Trump Show all 5 1 /5 Criminals who worked for Trump Criminals who worked for Trump Michael Cohen Former lawyer for Donald Trump was sentenced to three years in prison on counts involving evading income tax, false disclosure of the hush money paid to Stormy Daniels and another hush money charge Getty Criminals who worked for Trump Paul Manafort Former campaign manager for Trump Manafort was found guilty in February 2018 of five counts of tax fraud, two counts of bank fraud and one count of failure to disclose a foreign bank account. The crimes occurred prior to his appointment in Trump's campaign Getty Criminals who worked for Trump George Papadopoulos Former Trump campaign adviser Papadopoulos pleaded guilty to lying to the FBI in October 2017. He had lied about making contact with a professor who claimed that the Russians had dirt on Hillary Clinton. He was sentenced to 14 days in jail Getty Criminals who worked for Trump Michael Flynn Former White House National Security adviser Michael Flynn pleaded guilty to lying to the FBI in December 2017. He had lied about conversations that he had with the Russian ambassador to the US during Trump's Presidential campaign. He was not given prison time due to his "significant assistance" to the Mueller investigation Getty Criminals who worked for Trump Rick Gates Deputy chairman of Trump's presidential campaign Gates pleaded guilty to lying to the FBI in February 2018 AFP/Getty

In response to the attention, an attorney representing Ms Yang, Michelle Merson, said that her client is unaware of any wrongdoing.

"She is being accused of human trafficking, providing favours to Chinese politicians and businesses by selling access to the president," Ms Merson said in a statement to NBC News. "She's being accused of some very, very serious things that she is totally in the dark for… [and] she denies everything."

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Ms Yang sold the Orchids of Asia spa years ago, but maintains ownership of several other spas in southern Florida. Those locations have so far not been implicated in the sting that caught Mr Kraft up in alleged sexual misconduct.