Labour has called on Robert Jenrick to give up almost £40,000 donated to his campaign to be Conservative leader in 2024 following allegations that the sum came from an impermissible foreign donor now convicted of fraud.

The party called for Jenrick to make a donation to charity after the Guardian revealed the Electoral Commission has been investigating claims that £37,500 out of £100,000 given to his campaign by a UK company Spott Fitness ultimately came from a company run by a US-based businessman, Gary Klopfenstein.

The watchdog has also referred evidence to the police to assess whether any electoral laws have been broken. Its inquiries are now paused while the police review the material. The exact scope of the review is unclear and the police have not confirmed whether it relates to any specific individual. They could decide to open an investigation or take no further action.

Jenrick said he had no knowledge of whether Klopfenstein was behind any of the contribution, had never been in contact with him and had complied with all electoral laws. He also said he had no knowledge of any police review and said the Conservative party, which has referred Jenrick to the standards commissioner, had checked the permissibility of Spott Fitness as a donor and raised no concerns.

However, Labour said that Jenrick, now a Reform UK MP, should hand the £37,500 to charity, given the allegations that it came from a foreign source, especially now the businessman has been convicted of fraud. Klopfenstein pleaded guilty to one count of wire fraud in the US in the same month as the donation in July 2024, and is still awaiting sentence.

In a letter to Jenrick, Anna Turley, the Labour party chair, said: “Given that the Metropolitan police are now examining these donations, and given Mr Klopfenstein’s guilty plea, the public deserves to know whether you take these matters seriously.

“It is right therefore that you must confirm what due diligence you carried out before accepting these funds and whether you are prepared to donate the £37,500 in question to a charitable cause, so that no benefit is derived from money connected to a convicted fraudster.”

The allegations made to the Electoral Commission raise questions as to whether the donations were permissible within electoral law, given foreign companies and individuals are not allowed to donate to UK politicians or parties. Transparency around donations is a fundamental part of the UK electoral system so the public can know who is contributing money to fund political parties.

Until now, it had been thought the £100,000 was contributed by Phillip Ullmann, a UK businessman who revealed that Spott Fitness was part of his family’s group of companies when questions were asked about its ownership and a loan from another company, based in the British Virgin Islands, in 2024.

According to Ullmann, he gave information to the Electoral Commission in 2025 that £37,500 of the donation to Jenrick from Spott Fitness came from Klopfenstein – a former business associate with whom he is now in a legal dispute – through Innovyz USA. Klopfenstein is alleged to have transferred the money to Spott Fitness through Innovyz on 8 July 2024 and 24 July 2024.

At the time of the original report, a spokesperson for Jenrick said: “The suggestion that Robert knowingly accepted impermissible donations is an untrue, politically motivated smear, put about years later by the Conservatives, despite the fact that Mr Ullmann was introduced to Robert by a Tory MP, and had his donations’ permissibility checked by the party.

“Robert and his campaign team complied with all electoral laws when receiving the donation received from Spott Fitness Ltd in 2024. Mr Jenrick has never met, spoken to, or had any contact with Mr Klopfenstein, nor was he aware of any connection between him and Mr Ullmann’s donation until he was contacted by the Electoral Commission. He fully cooperated with the Electoral Commission inquiry, providing detailed records that categorically disproved these smears in 2025.

“The dispute between these two businessmen, which seems to be the cause of these claims, has nothing to do with Robert. He does not know anything about the police’s review of this matter and has not been contacted by them, but he would, of course, provide any assessment, if indeed there is one, with the same records he provided the Electoral Commission.”

A spokesperson for Ullmann said: “Mr Ullmann voluntarily disclosed additional information to the Electoral Commission … He has continued to engage proactively with their subsequent investigation ever since. He has fully responded to all the questions they have asked of him to date and stands ready to support the authorities in any way he can.”

Ullman’s position is that he was transparent about the source of the donation with the Jenrick campaign and that he was unaware of any potential problems with Klopfenstein’s contribution.

The Met said: “On Tuesday 6 January we received a referral from the Electoral Commission concerning donations connected to a leadership campaign. This referral is under review and until it has been completed, we are not in a position to comment further.”

The Electoral Commission said: “We have been investigating donations connected to a 2024 leadership campaign. Evidence of potential offences outside our remit was referred to the Metropolitan police service on 6 January 2026. Our investigation is paused pending their assessment. We don’t discuss the details of our investigations and cannot comment further at this stage.”