Police have been handed a photograph of Boris Johnson with a can of beer taken at his own lockdown birthday party, it has been reported.

The photograph is said to show the Prime Minister standing next to Chancellor Rishi Sunak, who is holding a soft drink, in No 10’s Cabinet Room, according to The Daily Mirror.

The image was reportedly taken by Mr Johnson’s official photographer, who was documenting the event.

It is thought to be among 300 pictures submitted to the Metropolitan Police in wake of the investigation by Sue Gray. 

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Downing Street had previously admitted staff “gathered briefly” at a surprise birthday celebration organised by the Prime Minister's wife Carrie Johnson - but said Mr Johnson only stayed 10 minutes.

It is claimed that Mrs Johnson led 20-30 staff in a rendition of happy birthday before tucking into picnic food from M&S.

The Chancellor is understood to have attended the event as he turned up for a Covid meeting, but had not been invited in advance.

Later that evening, Mr Johnson and his wife were said to have hosted family friends in their residence upstairs in an apparent further breach of the rules.

Downing Street denied these claims and insisted that the PM hosted a small number of family members outside instead.

A Downing Street spokesman said: “A group of staff working in No 10 that day gathered briefly in the Cabinet Room after a meeting to wish the Prime Minister a happy birthday.

“He was there for less than ten minutes.”