The investigation into whether Sir Keir Starmer broke coronavirus rules cost the public £101,000, police have said.
Durham Police launched an inquiry after the Labour leader was filmed drinking beer in an MP’s office in April 2021.
At the time there were Covid restrictions in place.
Sir Keir and his team were cleared of any wrongdoing in July.
A Freedom of Information (FOI) request to Durham Police has revealed the cost of the investigation was £101,000.
It took nine officers about 3,200 hours on the investigation.
The gathering in the office of Durham City MP Mary Foy, which took place in the lead up to the Hartlepool by-election, involved people drinking beer and eating curry.
Social distancing rules, including a ban on indoor mixing, were in place at the time.
However, Labour had said the food was consumed between work events, which meant the gathering was within the rules.
They were cleared in February of breaking the law but officers reopened the investigation in May after "significant new information" came to light.
The FOI revealed the investigation involved one detective superintendent, one detective inspector, one detective sergeant, six constables and two members of police staff.
About 3,203 hours were spent on the investigation.
The total operational cost was about £101,000 and came from the general policing budget.
Earlier this year, the then-Prime Minister Boris Johnson was fined for breaching lockdown rules in June 2020.
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