Former Labour minister Tulip Siddiq has accused the Bangladeshi authorities of mounting a “targeted and baseless” campaign against her.

In a letter to Bangladesh’s Anti Corruption Commission (ACC), the MP’s lawyers say allegations of corruption are “false and vexatious” and have never been formally put to her by investigators, despite being briefed to the media.

Siddiq resigned as economic secretary to the Treasury, with responsibility for tackling corruption in the UK’s financial markets, in January.

The Hampstead and Highgate MP insisted at the time she had done nothing wrong but that she did not want to be a “distraction” to the government.

In a letter accepting her resignation, Prime Minister Sir Keir Starmer, a close friend of Siddiq who represents a neighbouring constituency in North London, said the “door remains open” to her return.

Siddiq had referred herself to the PM’s ethics adviser Sir Laurie Magnus when the corruption allegations first surfaced in January.

Sir Laurie said in his report that he had “not identified evidence of improprieties”.

But he added it was “regrettable” that Siddiq had not been more alert to the “potential reputational risks” of the ties to her aunt Sheikh Hasina, the deposed prime minister of Bangladesh.

The ACC is examining claims Sheikh Hasina and her family embezzled up to £3.9bn from infrastructure spending in Bangladesh.

The investigation is based on a series of allegations made by Bobby Hajjaj, a political opponent of Hasina.

Court documents seen by the BBC show Hajjaj has accused Siddiq of helping to broker a deal with Russia in 2013 that overinflated the price of a new nuclear power plant in Bangladesh.

In its letter to the ACC, Siddiq’s lawyers, Stephenson Harwood, repeat her claim that she was not involved in the nuclear plant deal in any way, despite being pictured at a signing ceremony in the Kremlin in 2013, with Sheikh Hasina and Russian president Vladimir Putin.

“It is not uncommon for family members to be invited to accompany Heads of State on state visits,” the letter says, adding that she had no knowledge of any alleged financial irregularities.

It says claims that a £700,000 flat in London King’s Cross gifted to Siddiq in 2004 was “in some way the fruits of embezzlement” were “absurd” and “cannot be true” because it was 10 years before the nuclear deal.

In his investigation into the allegations, Sir Laurie Magnus said that “over an extended period, she was unaware of the origins of her ownership of her flat in Kings Cross, despite having signed a Land Registry transfer form relating to the gift at the time”.

She “remained under the impression that her parents had bought the property for her”, Sir Laurie added, but had to correct the record when she became a government minister.

He describes this as an “unfortunate misunderstanding” which meant the public had been “inadvertently misled about the identity of the donor of this gift”.

In their letter to the ACC, Siddiq’s lawyers confirm that the King’s Cross flat was given to her by Abdul Motalif, who is described as “an Iman and a very close family friend, akin to Ms Siddiq’s godfather”.

The letter also contains a detailed rebuttal of allegations made by the ACC to the media that Siddiq was involved in the appropriation of land in Dhaka.

It describes ACC briefings to the media as an “unacceptable attempt to interfere with UK politics”.

“At no point have any allegations been put to her fairly, properly and transparently, or indeed at all, by the ACC or anyone else with proper authority on behalf of the Bangladeshi government, ” the letter says.

“We require that you immediately stop manufacturing false and vexatious allegations against Ms Siddiq and further media briefings and public comments designed to harm her reputation.”

The letter says the ACC must put questions to Siddiq “promptly” and “in any event by no later than 25 March 2025″ or ” we shall presume that there are no legitimate questions to answer”.

The ACC’s chairman, Mohammad Abdul Momen, told The Times: “All allegations raised against Ms Siddiq will be proven in any court, including the ones in the United Kingdom.”