Undercover detectives are posing as drug pushers in "sting operations" to catch middle-class cocaine users, the Metropolitan Police commissioner says.
Sir Ian said he pledged to tackle 'dinner-party' cocaine users
Scotland Yard was using smartly dressed officers to catch more affluent drug takers, Sir Ian Blair told the Times.
It comes a day after Sir Ian apologised for using the Soham murders in 2002 to make a point about racism in the media.
The charity DrugScope said questions needed to be raised about whether the stings were a good use of police funds.
In an interview with the newspaper, Sir Ian said he wanted middle-class users of the Class A drug to recognise the impact their habit had elsewhere.
"Do you know that the greatest deployment of landmines in the world is by the cocaine growers in Colombia...
"People need to think that young men die in estates in North London so that someone else can have a wrap of cocaine."
The newspaper said the sting operations mostly took place in bars and clubs, monitored by hidden cameras.
When Sir Ian assumed control of Britain's biggest force a year ago, he said he wanted to stop cocaine replacing wine at dinner parties.
The commissioner told the Times: "What we are trying to do is make people understand that when they buy from a supplier... they find they are buying from a Metropolitan Police officer. And that is quite an upsetting experience, I understand."
The people caught were not celebrities, but they were also not the kind of person who would be buying cocaine from "a street dealer in Brixton", he added.
However, he told the paper that officers were unlikely to actively disrupt parties in a bid to stop drug use.
"I can't imagine the circumstances in which the men of the Yard are crashing through the door of a Hampstead dinner party," he said.
A Drugscope spokeswoman said: "Obviously drugs are of high priority for police forces up and down the country but they have limited resources.
"We have to question whether this is the best use of resources - to target individuals in this way.
"That is not to condone drug use in any way but we would argue that it's probably better to target larger scale drug users.
"The impact on disrupting those markets is going to be much greater on local markets than targeting individuals."
On Friday Sir Ian apologised "unreservedly" for any offence caused to the parents of Holly Wells and Jessica Chapman for his comments on the Soham murders.
He said while the murders of two schoolgirls in 2002 were "dreadful crimes", he remarked that "almost nobody" understood why it became such a big story.
He stood by his comments, which were made at the Metropolitan Police Authority's monthly meeting, that race impacted on the news agenda in the media.
Sir Ian was criticised by campaigners and some Metropolitan Police Authority members and media representatives over his views.