Treasury minister Tulip Siddiq has been named in an anti-corruption investigation in Bangladesh alongside her family.
Ms Siddiq is alleged to have been involved in brokering a 2013 deal with Russia for a nuclear power plant in Bangladesh in which large sums of cash were embezzled.
The Labour minister’s aunt, Sheikh Hasina, was until recently prime minister of Bangladesh for more than 20 years, and is facing a wider investigation by an anti-corruption commission in the south Asian country.
As economic secretary to the Treasury, Ms Siddiq is responsible for tackling corruption in the UK’s financial markets.
She has been approached for comment, and the Labour Party has declined to comment.
But sources close to the minister have described the allegations as “spurious”.
The investigation is based on allegations made by a political opponent of Ms Hasina, Bobby Hajjaj.
The former Bangladeshi leader was deposed in August, and is regarded by her critics as an autocrat.
They have since accused Ms Hasina, the leader of Bangladesh’s Awami League political party, of multiple crimes.
Ms Siddiq, the MP for Hampstead and Highgate, was first elected in 2015.
In court documents seen by the BBC, Mr Hajjaj accuses her of mediating meetings as part of a deal between the Bangladeshi and Russian governments to build the Rooppur Power Plant.
It is claimed that Ms Hasina and members of her family siphoned off cash from the deal for their own private use.
Associated Press footage from 2013 shows Ms Siddiq attending the signing of the deal between her aunt and Russian president Vladimir Putin at the Kremlin.