Downing Street has denied reports that Boris Johnson attended a "party" successful No 10 during outpouring past year.
Sources told the newspapers the premier curate joined the officials and advisers for astir 15 minutes.
They added that the then-Health Secretary Matt Hancock was besides seen astatine the event.
But a spokesperson for Mr Hancock said helium did not be a enactment and lone stayed successful No 10 aft the property league to debrief his squad and the PM.
Covid rules successful spot astatine the clip allowed lone 2 radical from antithetic households to socialise extracurricular successful nationalist places.
The reports travel aft a raft of parties successful No 10 and different authorities departments were revealed to person taken spot past Christmas, contempt coronavirus restrictions being successful place.
Mr Johnson - who was pictured connected surface astatine a Christmas quiz successful No 10, but insisted helium "broke nary rules" - ordered an inquiry, led by Cabinet Secretary Simon Case, into immoderate of the events.
The Metropolitan Police said connected Thursday that it was successful interaction with the Cabinet Office, adding: "If immoderate grounds emerges of behaviour that is perchance a transgression offence it volition beryllium passed to the Met for further consideration."
But the unit did corroborate it would beryllium "making contact" with 2 radical who attended a gathering organised by the squad of the Tory erstwhile London mayoral candidate, Shaun Bailey, connected 14 December 2020.
The latest study claims determination was an lawsuit successful No 10 connected Friday 15 May 2020, erstwhile the UK was inactive successful the archetypal lockdown.
The newspapers said immoderate unit had drinks astatine their desks, with others drinking successful the Downing Street garden.
They reported immoderate unit drank precocious into the evening - but added determination was nary proposition Mr Johnson oregon Mr Hancock drank themselves oregon stayed late.
Mr Hancock led the authorities property league from Downing Street connected that day.
The BBC understands unit successful Downing Street regularly had drinks astatine their desks connected a Friday successful their Covid-secure office.
In effect to the reports, a Downing Street spokesperson said that unit "regularly usage the plot for immoderate meetings" during summertime months.
They added that connected 15 May, Mr Johnson had held a "series of meetings passim the afternoon, including concisely with the past wellness and attraction caput and his squad successful the plot pursuing a property conference".
"The premier curate went to his residence soon aft 19:00," the spokesperson added.
"A tiny fig of unit required to beryllium successful enactment remained successful the Downing Street plot for portion of the day and evening."
A spokesperson for the erstwhile wellness caput besides told the BBC: "There is nary proposition that Mr Hancock did thing wrong.
"He arrived successful Downing Street that time astatine astir 16:40 to springiness a property conference, which took spot betwixt 17:00 and 17:53.
"After that helium debriefed his team, past went to the Downing Street plot to debrief the premier minister.
"He near Downing Street astatine 18:30 and went backmost to his department."
The authorities Christmas parties of 2020
13 November 2020: Sources person told the BBC determination were impromptu drinks to people the exit of the erstwhile manager of communications astatine No 10, Lee Cain - but it was unit having drinks astatine their desks and was implicit by 20:30 GMT.
13 November 2020: Also the day Dominic Cummings near arsenic main advisor to the PM. Sources told the BBC that respective Downing Street unit members attended a gathering with Carrie Johnson successful the level wherever the premier curate and his woman unrecorded supra No 11 aft exits. A root said euphony was blaring and could beryllium heard elsewhere successful the building. But others said to beryllium astatine the enactment denied it took place, arsenic did a spokeswoman for Mrs Johnson.
25 November 2020: The Times reported Treasury officials held a drinks enactment successful their bureau to observe Chancellor Rishi Sunak's spending reappraisal during the lockdown. The paper said 2 twelve civilian servants were understood to person attended the event. But a spokesperson for the section insisted it was an "impromptu" event, with a "small number" of unit who celebrated astir their desks.
27 November 2020: Another No 10 aide, Cleo Watson, near Downing Street marked by an event. Again, sources said it was not formally organised, but radical were having drinks and Mr Johnson made a speech.
December 10 2020: The Department for Education has confirmed it had a gathering successful the bureau to convey unit for their enactment during the pandemic. Drinks and snacks were brought by those who attended and nary extracurricular guests oregon enactment unit were invited.
14 December 2020: The Conservatives person confirmed a study successful the Times that determination was an "unauthorised societal gathering" successful the basement of their party's building, held by the squad of the London mayoral campaigner astatine the time, Shaun Bailey. It was described arsenic "raucous", with No 10 aides
15 December 2020: Multiple sources told the BBC determination was a Christmas quiz for No 10 unit successful the Cabinet Office, with invites sent retired successful beforehand via email, telling radical to signifier teams of six. Downing Street person said it was a "virtual gathering" but portion immoderate joined successful that way, sources said determination were groups successful the country sat successful their teams. This is the lawsuit the Sunday Mirror released a representation of the PM attending virtually.
18 December 2020: A Downing Street Christmas enactment took spot connected this date, arsenic archetypal reported by the Mirror. A root told the BBC determination was food, drinks and games astatine the gathering that went connected past midnight.
DWP gatherings: The Department for Work and Pensions confirmed a "core team" of unit drank intoxicant and ate takeaways "on a fig of occasions" whilst moving precocious successful the bureau portion Covid restrictions were successful place. It followed a study successful the Sunday Mirror alleging governmental unit and officials moving for curate Therese Coffey often drank aft enactment until the aboriginal hours of the morning.