On the eve of the Olympic Games, nearly a dozen Romanian officers, including detectives, have been seconded by Britain's biggest police force.
The 10 officers will work with Scotland Yard over the next three months to counter the wave of petty crime throughout the capital.
The Romanian officers, who all speak English, have been especially recruited due to their knowledge of the Roma community.
They also have access to intelligence systems in Romania but they will not have police powers while on patrol in London.
Seven officers will patrol throughout Westminster and the West End in uniform to deal with gangs of beggars who have been camping out in central London
The Roma travellers, including young children and pregnant women, have been living around Marble Arch and Park Lane for the past two months.
Since November last year almost 700 Romanian nationals have been arrested throughout the area.
Bernard Hogan Howe, the Metropolitan Police commissioner, said the officers would be available to units across the Met to support Romanian victims of crime and assist in cases where suspects originate from Romania.
"This work will include obtaining intelligence, assisting in the identification of offenders, helping with interview procedures, and supporting pre-planned operations," he said.
"It is hoped the initiative will prove beneficial for both police forces with the officers gaining experience in how the Met operate.
"The Met (are) making the most of the officers' skills and expertise, which will prove invaluable when dealing with those issues affecting the Romanian community within the capital."
Boris Johnson, the Mayor of London, said: "These Romanian officers will prove to be a huge asset in cracking down on certain criminal networks who are targeting tourists in central London.
"We are only days away from the Olympic Games and this initiative will help to keep our streets safe."
The scheme was launched in London yesterday by Dr Ion Jinga, the British Ambassador for Romania.
He said: "The current project is part of a broader approach based on exchanging best practices and fighting criminality.
"We are very keen to protect the good reputation of the Romanian citizens living in the UK."
The officers will be deployed for three months in a pilot project, three of whom will work with trafficking teams.
Mr Hogan Howe will visit Romania later this year as one his first international visits.