The Metropolitan Police is “considering” calls for it to investigate so-called cash for honours allegations linked to Conservative Party peerage appointments.
But the force said it had not yet started an investigation into the claims made in the media and raised in Parliament by SNP MP Peter Wishart.
The party’s Commons leader has confirmed he has written to Metropolitan Police Commissioner Dame Cressida Dick to raise “potential criminal misconduct regarding the procurement of honours and membership of the House of Lords”.
He wants a police probe to focus on an Open Democracy and Sunday Times investigation which, among other claims, found nine of the party’s former treasurers have been elevated to the House of Lords since the Conservatives returned to power in 2010.
A spokesman for the Met said: “The MPS (Metropolitan Police Service) has received correspondence relating to recent media reports concerning the awarding of peerages.
“At this time, we are considering the contents of the correspondence.”
Mr Wishart said he was “not accusing anyone of anything” in asking the Met to investigate allegations that Tory donors had been given seats in the upper chamber.
He told Sky News: “What we’ve done in the course of the past few days is the Pandora’s box marked Tory sleaze has been opened for full examination, and what a rotten septic cesspit we found that to be.”
But Dominic Raab insisted there was “absolutely no question” of the Government being involved in a cash for honours scandal.
The Justice Secretary and Deputy Prime Minister said opposition parties were making “political points” by asking police to investigate, following reports that Tory donors who had given more than £3 million to the party had been elevated to the Lords.
He told Sky News no-one was suggesting any wronging in regard to political donations.
Mr Raab added: “In relation to becoming appointed to the House of Lords, there’s also very clear rules.
“I would just say that, of course, people who are entrepreneurs but also engaged in public service, whether that’s charities, whether that’s supporting political parties, do a public service.
“And certainly we benefit when the Conservative Party has a treasurer… people who’ve got that kind of experience.”
During his Sky interview, Mr Wishart was forced to defend a complaint about a £600,000 Scottish independence fund which is under investigation.
He said: “There has been, obviously, a complaint about money that was given to the Scottish National Party, which is still available for an independence campaign, from accounts which have been properly accounted for and given to the Electoral Commission.”
The peerages claims come amid a sleaze row after the Government attempted last week to rip up the current parliamentary standards system to delay the suspension of former cabinet minister Owen Paterson.
But ministers opted to U-turn on the move after opposition parties made clear they would not back the reforms, leading to Mr Paterson choosing to resign as Tory MP for North Shropshire.