The prominent Reform UK member and Brexit campaigner Arron Banks is said to have set private investigators on a Sunday Times journalist after he broke a series of stories about Nigel Farage.

Banks is alleged to have paid for the services of investigators to examine Gabriel Pogrund, editor of the paper’s Insight investigations team.

The detail emerged in the New Statesman on Friday. When approached for comment, Banks did not appear to deny it. He is said to have instructed Precision Risk and Intelligence, a firm he once owned, to examine Pogrund.

The Sunday Times and the Guardian have broken a series of stories in recent months revealing how cash has poured into Reform and Farage personally from donors and wealthy benefactors.

Pogrund is believed to have been targeted after a story in the Sunday Times last month revealed that Farage has received financial support from the convicted criminal George Cottrell, known as “Posh George”.

In response to the New Statesman report, Banks said: “We believe the Sunday Times used hacked information and that was an area of interest. We do have an investigative arm that’s got advanced capabilities.”

Asked directly whether he had paid investigators to look into Pogrund, he said: “When you live by the sword, you die by the sword.”

The Sunday Times last night denied the accusation that its stories were based on illegally sourced information. The paper described the hiring of private investigators to snoop on its journalists as “reprehensible”.

A spokesperson said: “If what Mr Banks claims to have done is true then it is reprehensible that his reaction to our reporting is to place a journalist under surveillance … This story was not based on hacked information. It was based on responsible and professional journalism.”

The gifts the Reform UK leader Nigel Farage received in the 12 months before being elected as MP for Clacton have been subject to widespread media scrutiny in recent months.

MPs are obliged to declare any political donations they received in the year before their election but Farage has repeatedly claimed that it was not until the month before the general election, in July 2024, that he decided to stand. He has claimed he was not obliged to declare any donations he received before deciding to run for election, as he was a media personality at the time.

In April, the Guardian reported that he had accepted a £5m gift from Christopher Harborne, a billionaire donor to Reform UK.

The Sunday Times has reported that Cottrell paid for security, accommodation and social media support for Farage during this time. The newspaper also said that Cottrell helped to broker a “comeback deal” for Farage to return to Reform as party leader months before he announced he would stand.

Cottrell’s mother, the retired stylist Fiona Cottrell, made a series of donations to Reform UK in the weeks before the general election. Two transfers of £250,000 were made directly to the party in May 2024.

She then gave £1m to Britain Means Business, a company owned by Reform UK’s deputy leader, Richard Tice. Britain Means Business gave the party two donations of £250,000 shortly afterwards.

The Guardian told how they later became the subject of a suspicious activity report by the National Crime Agency. Suspicious activity reports are not crime reports but exist to identify potential incidents of money laundering.

The Metropolitan police are investigating Reform UK’s finances. The Guardian revealed that both George and Fiona Cottrell have been interviewed under caution but no arrests have been made.

On Saturday morning, the Guardian asked Banks if Reform UK had known about or sanctioned the surveillance on Pogrund, or if any other journalists had been targeted.

“I have nothing else to add,” he said. “Other than to say I have spoken to no one at Reform on this matter, nor would I.”

Reform UK was contacted for comment.