The investigation into COVID-19 lockdown parties held at British Prime Minister Boris Johnson's Downing Street office has ended, police said Thursday, adding that they had issued a total of 126 fines.

Johnson and his Finance Minister Rishi Sunak were both fined last month over a gathering in his office to celebrate his 56th birthday in June 2020 when social mixing was all but banned. It led to widespread calls from opposition politicians and some in his own party for him to resign.

"Our investigation was thorough and impartial and was completed as quickly as we could, given the amount of information that needed to be reviewed and the importance of ensuring that we had strong evidence for each FPN (fixed penalty notice) referral," London Police acting Deputy Commissioner Helen Ball said.

Police said their investigation, which involved 12 officers who examined 510 photos during their inquiries, had now concluded. Of the 126 fixed penalty notices issued, 53 were given to men and 73 to women, with some people receiving more than fine.

A Downing Street source said Johnson had not received notification of another fine "at this stage."

"This investigation is now complete."

Police also said the fines related to eight dates when events were held at Downing Street and other government offices between May 2020 and April 2021 when lockdown measures were in place to prevent the spread of the coronavirus.

Of those fined, 53 were men and 73 were women, with some people receiving more than one.

Some of the parties took place while lockdown conditions had forced the closure of restaurants, pubs and businesses, and meetings with friends and family, including for funerals, were severely restricted. About 180,000 people have died in Britain from COVID, the seventh highest toll by country in the world.