Media playback is unsupported on your device Media caption Police searched a property in central London using sniffer dogs

Police have launched a criminal investigation after former Deputy Lords Speaker Lord Sewel was filmed allegedly taking drugs with prostitutes.

The Metropolitan Police said it was looking into "allegations of drug-related offences involving a member of the House of Lords".

It said a search warrant was executed at 18:00 BST at a central London address and no arrests had been made.

Lord Sewel is to be granted a "leave of absence" from the House of Lords.

He has already quit as deputy speaker and chairman of the Lords privileges and conduct committee.

Lords officials referred the matter to the police.

'Not a resignation'

The Met said the warrant under the Misuse of Drugs Act was granted by Westminster Magistrates' Court.

Police with sniffer dogs and a battering ram were seen at a building in central London.

Image caption A police officer is seen at the address carrying a battering ram

News of the criminal investigation came after Lord Sewel said he would not attend the Lords until the outcome of any investigation into his conduct, after which he would review his "long-term position".

During that time, he will not be able to claim any expenses or allowances.

There have been calls for him to be expelled or to quit the Lords.

BBC political correspondent Ross Hawkins said requesting a leave of absence was "not a resignation, not a throwing in of the towel. It's an acceptance that it may not be possible for him to return to the red benches until the investigation is complete".

Image copyright Sun on Sunday Image caption Lord Sewel has taken a leave of absence from the House of Lords

Lord Sewel was appointed as a Labour peer in 1996 but has sat as a non-affiliated (independent) peer since taking up his standards role.

The original footage, released by the Sun on Sunday, appeared to show Lord Sewel snorting powder from a woman's breasts with a £5 note.

The Sun then published further photographs of the peer in Monday's newspaper, along with details of new footage in which he is said to make disparaging remarks about a number of other politicians.

New rules

Image caption Lord Sewel held the role of chairman of committees in the Lords

Under new rules which came into force earlier this year, peers can be expelled if they are found to have breached the code of conduct that all members are expected to uphold.

The code requires members to act in the public interest, and in accordance with the seven general principles of conduct identified by the Committee on Standards in Public Life - selflessness; integrity; objectivity; accountability; openness; honesty and leadership.

But any investigation into the case is likely to take months and will not begin until any criminal proceedings are completed.

In the past, peers have been temporarily suspended for expenses fraud, lobbying scandals and other misconduct but have all ultimately returned to the House of Lords.

What are the rules for Lords?

As the House of Lords is currently in recess, the leave of absence will take effect from 7 September, when peers return.

Under the rules, he will have to give three months' notice before returning.

"I wish to take leave of absence from the House as soon as it can be arranged," Lord Sewel said in a letter to the Lords authorities.

"I also wish to make clear that in doing so I have no intention of returning to the House in any way until the current investigations have been completed, when in the light of their outcome I will review my long-term position.

"I believe this is compatible with due process."

Baroness D'Souza, the speaker of the House of Lords, has written to Lords Standards Commissioner Paul Kernaghan asking for an investigation.

He is expected to decide in the next 48 hours whether to look into the allegations.

Lib Dem president Baroness Sal Brinton said Lord Sewel should "resign immediately", while former Commons Speaker Baroness Boothroyd said he should "take a quiet way out of the back door of the House of Lords".