Prosecutors world-wide are too lenient on celebrities who use drugs, sending a dangerous message to young people, the United Nations said in its global report on illegal narcotics trends.

SHOWS: LONDON, ENGLAND, UNITED KINGDOM (REUTERS) - The U.N. International Narcotics Control Board said on Wednesday (March 5) overall drug usage appeared stable, but soaring opium production in Afghanistan was fuelling heroin use in its neighbours and globally.

It also warned that drug smugglers were increasingly using West Africa as a transit point to bring cocaine and other substances into Europe from Latin America by air and sea.

The board said too many governments disproportionately targeted ordinary addicts and street dealers while doing too little to tackle the larger narcotics gangs -- and letting high-profile users walk free.

"Governments -- they do a lot of activities and they demand deductions, reducing the demand for illicit drugs and then if a few celebrities, if they give that messages to the young people, undermines all of the other activities which the government does to demand deductions," said board member and report author Hamid Ghodse said in London.

He refused to name any particular individuals or countries considered too soft on famous users.

"In a sense, we need to be tougher on those who are role models in whatever context they are in if they are caught with it. It's not just exposure in the tabloids, I think the authorities need to be very tough," said Steve Rolles, Transform Drug Policy Foundation.

To be effective, authorities must get tougher on those at the top of the illicit drug trade, Ghodse said, adding that because this was not easy, many law enforcers chased the easy pickings at the bottom of the pyramid.

Overall, Ghodse said, more co-ordination across borders was key to cracking the trade. But he said the situation in the world's fastest growing drug producer Afghanistan, now producing more than 93 percent of global opiates, was out of control.

During Prime Ministers Questions at the House of Commons on Wednesday (March 5), Gordon Brown said that despite the number of reported drug cases decreasing in the United Kingdom, celebrities still had a responsibility to send the correct message out about the dangers of drugs.

"One of the good things in recent years is that the number of people using drugs has fallen in recent years. It is also true that the number of people undergoing drug treatment is up. And we have doubled the budget for the amount of people using drugs. But I have to agree with him that it is very important when there are celebrities and role models for young people that they send out the proper messages. Some of our celebrities and role models are sending out the right message about the damage of drugs but I hope those people who take a casual attitude to drugs will think again and think about the message they are sending out to young people in our country," said Brown.

Despite attempts to curb poppy growing, opium production has grown steadily from a low point in 2001, shortly before the Islamist Taliban were ousted by U.S.-led forces.

The report attributed the world's highest addiction rate -- almost 3 percent of adults in Iran -- on Afghan heroin.

INCB said part of the problem was that key chemicals used in refining opium into heroin were being freely allowed into Afghanistan. Drug control has become secondary as U.S., NATO and Afghan forces try to stop a resurgent Taliban in the southern drug producing provinces.

Opiates such as morphine can serve a medical purpose as painkillers -- but Ghodse said legal demand for medical opiates would not come close to soaking up Afghanistan's current 8,200 tonne crop.