The Labour leader was accused of a covid rule breach while campaigning in Durham, after he was pictured drinking a beer after a day’s campaigning.

Sir Keir always denied breaking the rules, and he and his deputy Angela Rayner pledged to resign if they were found to have broken the rules.

Now, Freedom of Information data shows nine detectives from Durham Constabulary’s major crime team spent 3,200 hours investigating the allegations – which Sir Keir was later cleared of – at a cost to the taxpayer of more than £100,000.

Labour leader Keir Starmer during a press conference at the headquarters of the Labour Party in Victoria, central London, after Durham Police said that he and his deputy Angela Rayner have not been issued with fixed penalty notices for alleged lockdown regulation breaches while campaigning in April 2021. Picture date: Friday July 8, 2022.

Nine detectives and other staff from the major crime team – who normally investigate murders and serious sexual assaults – were drawn into the investigation.

All Labour staff were cleared of any wrongdoing in July 2022 following the investigation.

The force announced in May 2022 it was reopening the case, after coming under significant pressure, despite previously deciding no rules had been broken.

An exclusive FOI request by National World showed one detective superintendent, one detective inspector, one detective sergeant and six detective constables, alongside two other members of police staff were involved in the re-investigation. All 11 were from the force’s major crime team.

Sir Keir has previously said he “hated” being subject to a criminal investigation.

He said waiting to hear the outcome was a “burden every day”.

"I hated it, I am not like other people in many respects that will say it doesn’t matter, it meant a lot to me, it was a burden I was carrying. I tried not to show it of course, but it was there every day."

NationalWorld also put the same questions to Durham Constabulary regarding its investigation into former Downing Street aide Dominic Cummings, who drove his family from London to Barnard Castle and back again between March and April 2020 despite strict lockdown measures.

The force said it does not have an estimate of the cost or hours spent on this investigation.

But it did say one detective chief superintendent worked on the investigation alongside four further detectives (who assisted the senior investigating officer whilst continuing to perform other detective duties) and a member of police staff.

The force pointed to ‘beergate’ involving multiple suspects as the reason for the higher number of officers involved in that case.

Sir Keir Starmer 'beergate' investigation cost taxpayers £100,000