The force issued a total of 126 fines following its inquiries, but the Prime Minister will face no further action after being issued with a fixed penalty notice last month.
Liberal Democrat MP for North Shropshire Helen Morgan said the investigation found more breaches of Covid laws in Downing Street than any other address in the country.
“It exposes a shocking level of criminality at the heart of Johnson’s Number 10 while families across North Shropshire were making huge personal sacrifices," she said.
“Now the investigation has concluded the Sue Gray report should be published immediately and the parliamentary inquiry should be launched into Boris Johnson’s lies.
“It is astounding that Conservative MPs are allowing our great country to be run by a prime minister who broke the law then repeatedly lied about it.”
Craig Williams, MP for Montgomeryshire, said he hoped the conclusion of the investigation and the publication of the Sue Gray report would allow the focus to return to other matters.
"I welcome news that the investigation has come to its conclusion," he said.
"I now want to see the full copy of the Sue Gray report officially published, so we can go back to focusing on more substantive matters."
Mark Pritchard, Conservative MP for The Wrekin, said he welcomed Downing Street's commitment to publishing the Sue Gray inquiry in full.
But he said it was right and proper that similar scrutiny was applied to claims that Labour leader Sir Keir Starmer and his deputy Angela Rayner had also broken rules at an event in the office of Labour MP Mary Foy.
"I hope the Labour Party will offer the same transparency regarding the opposition leader's activities in Durham," he said.
Ludlow MP Philip Dunne declined to comment on the findings of the police investigation, saying he was awaiting the final Sue Gray report which he expected to see next week.
"I'm sure it will be published, she may want to make some changes as a result of the police investigation. It will be published when she wants to deliver it, but I imagine that would be by next week."