The Scottish Government says the merger would make railway policing more accountable.
Police Search Lord Sewel's Flat After Drugs Probe
Police investigation underway into allegations a Lord Sewel took cocaine while cavorting with prostitutes.
A uniformed police officer was on guard outside the door of Nelson House, Dolphin Square, London, last night following two days of lurid accusations against Lord Sewel.
The former Labour minister has requested a leave of absence from the House of Lords while investigations are carried out, promising not to enter Parliament or claim allowances - but left the door open to a future return to the red benches.
A search warrant was carried out on his central London property at 6pm but the Metropolitan Police said no arrests have been made at this stage. After a three-hour search detectives were seen leaving the property carrying several bags of evidence.
A uniformed officer left carrying a battering ram.
A standards watchdog in Parliament has also been handed the case following complaints from both Lord Speaker Baroness D'Souza and Liberal Democrat party president Baroness Brinton.
Lord Sewel has faced intense pressure to quit the House of Lords entirely following the allegations, revealed over two days in The Sun on Sunday and The Sun.
Prime Minister David Cameron led questions over the peer's future in Parliament, while Labour suspended his party membership.
Confirming its investigation, which began before a complaint was received, a Scotland Yard spokesman said: "The Metropolitan Police Service has today, Monday, July 27, launched a criminal investigation into allegations of drug-related offences involving a member of the House of Lords.
"A warrant under Section 23 of the Misuse of Drugs Act 1971, was today granted at Westminster Magistrates' Court.
"The warrant was executed at 6pm at an address in central London by officers from the Special Enquiry Team of the Homicide and Major Crime Command (HMCC).
"No arrests have been made at this stage and enquiries are ongoing.''
Earlier, Lord Sewel asked Clerk of Parliaments David Beamish for a leave of absence - a move which can be reversed with three months notice.
He said: "I wish to take leave of absence from the House as soon as it can be arranged.
"I also wish to make clear that in do 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.``
The peer's decision came after he quit his #84,500 a year role as deputy speaker of the Lords, a role which had involved overseeing standards in the Upper House.
Mr Cameron said the allegations against him were "very serious'', telling reporters in Jakarta: "I think it's right he has stood down from his committee posts and I'm sure further questions will be asked about whether it is appropriate to have someone legislating and acting in the House of Lords if they have genuinely behaved in this way.''
The newspaper's footage shows the peer snorting white powder - alleged to be cocaine - from a prostitute's breasts using a £5 note.
He is also pictured wearing an orange bra and leather jacket as he reclines smoking a cigarette.
The 69-year-old apparently paid one of the women for the night with a cheque for £200, dated July 22.
In a conversation reportedly recorded in Lord Sewel's Dolphin Square flat, a couple of miles from Parliament, the peer branded Mr Cameron "the most facile, superficial prime minister there's ever been'' and labels Mayor of London Boris Johnson "a joke''.
Lords commissioner for standards Paul Kernaghan, a former police chief constable, is also carrying out an initial assessment of the allegations.
He is expected to decide within 48 hours whether to launch a full investigation that could lead to the peer being expelled from Parliament.
Police sources earlier indicated they would assess the evidence after the referral from Baroness D'Souza, but pointed out that drug-taking allegations were notoriously difficult to prove when there was only video evidence, rather than substances that could be tested.
Former Commons Speaker Baroness Boothroyd said the peer had "brought the House into some disrepute'' and should "take a quiet way out of the back door of the House of Lords''.
Shadow business secretary Chuka Umunna said the peer should "fall on his sword'' if the allegations are proven.
Lib Dem president Baroness Sal Brinton said the peer should "resign immediately''. She added: "Lord Sewel's comments about women, and about Asian women in particular, are sexist and racist, and have no place in society.
"His comments and conduct expose a man with little regard for women and a total disregard for the status and responsibility of his role.''
Grants ranging from £500 up to £10,000 are being allocated to 494 grassroots organisations across the country.
A HMICS report on how the service is managed and delivered by the SPA makes 23 recommendations for improvement.
RF said progress was crucial with just over a million people in Scotland living in poverty.
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