Times Higher Education (THE) reporter Grove said he had been investigating allegations Arday had plagiarised parts of his PhD, and contacted him in 2025 to offer him the right of reply.

"In early February I received a call from a Met police officer saying that a complaint had been raised against me by someone and Professor Arday was very distressed and I shouldn't contact him again," Grove told BBC Radio 4's Today programme.

"It was a complete shock. Apparently it was for harassment but I hadn't contacted him for four months and then maybe I think I've only sent three or four emails to him in total."

The Met closed its inquiries into the case.

Sir Mark told LBC: "We dropped the ball on that one, let's not beat around the bush.

"A report came in of harassment or some crime like that, it should have been screened out as not requiring investigation...

"We shouldn't have made that call to him [Grove] and said that."

The University of Cambridge said on Tuesday it had begun an investigation into Arday, who became the institution's youngest black professor in 2023, following "new information" about his "academic qualifications and honorary appointments".

In a statement published by campaign group Good Law Project on Wednesday, Arday said the "relentless accusations, speculation and public commentary have taken a profound toll on me and on those I love".

"I no longer wish to feel as though I am living under a constant spotlight, where every aspect of my life is subject to public examination and judgement," he said.

Speaking of his decision to step down he added it should not "be mistaken for an acceptance of the narratives that have surrounded me".

His resignation followed a series of media reports alleging he plagiarised parts of his PhD thesis completed at Liverpool John Moores University (LJMU) and other research.

LJMU - which awarded his PhD in 2015 - had investigated the allegations that were made last year, but did not uphold the charges.

The Times reported Arday defended himself by arguing that he had not received adequate supervision during his PhD given his autism and "learning disabilities".

In an interview with the Times, Arday said that he could not afford a proofreader to catch mistakes when he started out in academia.

Further questions were raised in the press about the truth of other claims, including Arday saying he ran 600 miles in six days and that he raised £5.5m for charity.