The Taleban's fight against opium production in Afghanistan was the "most effective" drug control policy of modern times, research suggests.
An old Taleban notice warns against narcotics use and production
During the 1990s, Afghanistan was the main source of the world's illicit heroin supply.
But a UK study has found a Taleban crackdown on drugs led to global heroin production falling by two-thirds in 2001.
However, it notes that such draconian methods could not be used elsewhere.
Most Afghan heroin production was smuggled illegally to the West and to neighbouring Pakistan and Iran.
But from July 2000 until its downfall over a year later, the Taleban regime enforced a ban on cultivating opium poppy - from which heroin is manufactured.
The new report, written by criminologist Professor Graham Farrell from Loughborough University, has not yet been published, but the BBC has seen its findings.
Professor Farrell said the Taleban's methods were successful because of the manner in which the fight was implemented at a grassroots level.
"It was a set of fairly simple techniques - the threat of eradication and the punishment of transgressors with fairly harsh punishments," he told the BBC's World Today programme.
"What was particularly interesting was the manner in which it was implemented at the local level."
Production up again
Local community groups and religious leaders were made to implement the Taleban's policies and could be punished themselves if anyone was found cultivating opium poppies in their area, he said.
Farmers who refused to comply with the policies had their faces blackened and were jailed.
In extreme cases they were paraded through the streets.
The study said the result was that poppy growing in Taleban-controlled areas almost ceased and that globally, the heroin supply fell by 65%.
But since the Taleban was deposed, poppy cultivation has increased sharply.
Mr Farrell said the success of the strategy raised important questions about drug policy and policing.
But he said it would not be desirable nor possible to take such draconian measures elsewhere.