A police notice deterring pickpockets has gone up in one of the busiest shopping areas in Britain – written in Romanian.

The bright yellow sign, outside Covent Garden Underground station in Central London, states: ‘Ofiteri de politie in civil opereaza in aceasta zona.’

Put up by the Metropolitan Police, it translates as ‘plainclothes police officers operating in this area,’ and is believed to be the first time a force has put up a warning sign of this nature in Romanian.

Covent Garden is a mile away from Hyde Park Corner – notorious for the scores of Romanian rough sleepers who have made the affluent area their home.

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Crackdown: The bright yellow sign in Romanian put up outside Covent Garden Tube Station warns 'plainclothes police officers operating in this area'

Yesterday thousands of Christmas shoppers descended upon the area, and the crackdown by the Met is to dissuade gangs of thieves believed to be targeting large crowds of people hitting the shops before the festive holiday begins.

Across Britain a minority of Romanians have been responsible for aggressive begging, pickpocketing and fraud, but the problems have been particularly bad in the capital.

This year it was revealed that half of the pickpockets caught on the Tube were from Romania.

Mark Field, Conservative MP for Cities of London and Westminster, said: ‘It is important to make it clear that this type of activity is not welcome on our shores. There are Romanian people here who can’t speak English and shouldn’t even be in this country if they are not seriously looking for work.

‘This is an essential move by the Met Police to make it clear that we’re on their case.

‘Those people who are coming here with no intention whatsoever to contribute to the British economy should be removed at the earliest possible opportunity, particularly if they’re guilty of aggressive begging or pickpocketing.

The signs have been put up in Covent Garden, which is just a mile away from where scores of Romanian rough sleepers have made their home

‘There are many Romanians coming to this country willing to work, but I’m afraid there is a minority on the streets who should be removed.’

The Met would not confirm how many signs it has put up or in what languages they have been written.

Jack Gordon, chairman of Hyde Park Safer Neighbourhood Ward Panel, said: ‘People around here are fed up with the pickpocketing – the place has turned into Fagin’s kitchen.

‘The crime has a hugely negative effect on tourism, on trade and on the residents. The problem is very difficult to deal with and I suppose the police are trying to prevent a crime from happening rather than deal with it afterwards.’

EU restrictions on migration to the UK from Romania were lifted in January. Earlier this year, The Mail on Sunday revealed that the number of homeless Romanian migrants in some of the wealthiest areas of the capital had trebled.

In May, Treasury Chief Secretary Danny Alexander called warnings of a rise in Eastern European migration ‘inflammatory rhetoric’ and ‘scaremongering’. His comments came in response to official figures showing the number of Bulgarians and Romanians working in the UK had fallen by 4,000 in the three months since employment restrictions were lifted.

Figures for the whole of 2014 are not available yet but are expected to show a significant rise in the numbers coming from these countries.