The Metropolitan Police has insisted it has not delayed publication of the Sue Gray report into possible lockdown breaches in Downing Street and Whitehall.
Officers have received the material requested from the Cabinet Office to support their investigation.
Scotland Yard said police would now examine the material "without fear or favour" to establish whether any rules were broken, adding it had not delayed publication of the "partygate" papers.
Commander Catherine Roper, who leads the Met's Central Specialist Crime Command, said the timing of the document's release was a matter for the Cabinet Office.
Downing Street declined to comment on the Met statement.
The Cabinet Office did not offer further comment on when the report would be published.
It said Ms Gray's investigation continues, there is ongoing contact with the police and the findings will be made public. The department added that it would not speculate further on the inquiry being carried out by the senior official.
Ms Roper said the force had asked for "minimal reference" to be made in the report to the "relevant events", in order to "protect the integrity of the police investigation" and be "as fair as possible to those who are subject to it".
"This will only be necessary until these matters are concluded, and is to give detectives the most reliable picture of what happened at these events. We intend to complete our investigations promptly, fairly and proportionately," she said.
"We have not delayed this report and the timing of its release is a matter for the Cabinet Office inquiry team."
SNP Westminster group leader Ian Blackford tweeted: "No one will accept a Westminster cover-up.
"If the UK government refuses to publish the full unredacted report it will prove, yet again, that Westminster is utterly corrupt and broken beyond repair.
"It won't save Boris Johnson's skin. It will only add to the calls for him to go."
And Liberal Democrat leader Sir Ed Davey said: "Anything short of the full report would be a Whitehall whitewash not worth the paper it is written on."
The Met previously argued the constraints on the Cabinet Office report into "partygate" were necessary to "avoid any prejudice to our investigation", indicating it faced being watered down or a lengthy delay.
Ken Macdonald, a former director of public prosecutions (DPP), said earlier on Friday that the move seemed "disproportionate" in the face of "very powerful" public interest in the report's swift publication.
Veteran Tory MP Sir Roger Gale, one of the Conservatives to call for Mr Johnson's resignation, described it as a "farce" which could delay a possible challenge to the "lame duck" Prime Minister.
Opposition politicians warned of a "stitch-up" amid growing calls for the official report into potential Covid breaches in Downing Street and wider Government to be published in full, with it having the potential to trigger a vote of no confidence in Mr Johnson.
In its previous statement on Friday morning, Scotland Yard said: "For the events the Met is investigating, we asked for minimal reference to be made in the Cabinet Office report.
"The Met did not ask for any limitations on other events in the report, or for the report to be delayed, but we have had ongoing contact with the Cabinet Office, including on the content of the report, to avoid any prejudice to our investigation."
Rather than the statement indicating an escalation of the investigation, the PA news agency learned officers were looking into possible breaches of Covid rules that may warrant fixed penalty notices, with the Met's concerns centring on the ability of officers to effectively investigate.
The new statement, issued on Friday evening, contained no mention of the term "prejudice".
Ms Roper said the offences under investigation, where proven, would normally result in the issuing of a fixed penalty notice.
"Individuals who are identified as having potentially breached these regulations will normally be contacted in writing and invited to explain their actions including whether they feel they had a reasonable excuse," she said.
"Following this process, and where there is sufficient evidence that individuals have breached the regulations without reasonable excuse, officers will decide if enforcement action is appropriate.
"If the decision is to take enforcement action then a report will be sent to the ACRO Criminal Records Office which will issue the fixed penalty notice. Recipients can pay the fixed penalty and the matter will be considered closed.
"Should a recipient dispute the fixed penalty notice then the case will be referred back to the Met where officers will consider whether to pursue the matter in a magistrates' court.
"As the Commissioner said, we will not be giving a running commentary but we will continue to update when significant progress is made in the investigative process."
Sources close to the Gray inquiry have previously indicated the senior civil servant was concerned about the prospect of releasing a report that was shorn of some of its key findings.
Officers have not confirmed how many events they are investigating, but reports have suggested it could be as high as eight.
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