Cocaine seizures have quadrupled

The force confiscated 360kg of cocaine in the financial year 2003 to 2004, compared with 96kg the year before.

Heroin dealers are thought to be switching to cocaine because it is more profitable, says the National Criminal Intelligence Service (NCIS).

Police say figures show a "significant success" in the fight against drugs.

An NCIS spokeswoman added there was evidence of more cocaine destined for Britain being seized in Europe.

But she said it was largely due to better co-operation between European police forces.

'Devastating impact'

The Metropolitan Police and Customs and Excise are setting up a new pan-London drugs unit which will start work later this year.

It will target those importing and supplying hard drugs.

Police say it will provide an "innovative approach" to disrupting dealing on the streets and will help confiscate dealers' money.

Over the past year police say �4m has been seized from drug dealers - 50% of all money earned by criminal activities seized in London.

The figures also show crack cocaine seizures rose from 11.3kg in 2002 to 2003 to 17kg the following year.

Over the same period heroin seizures dropped from 105kg to 43kg.

Assistant Commissioner Tarique Ghaffur said class A drugs had a "devastating impact" on local communities.

He said: "The very presence of drugs on the streets of London cause increased levels of crime as addicts turn to robbery, burglary and alike, as a means of feeding their habit."