Decriminalising drugs in Portugal cut addiction by 50%, the country's national drugs co-ordinator said.
Joao Goulao told BBC Radio 4's Today programme: "We had around 100,000 people hooked on heroin, which is 1% of our population, and now we estimate that we have half of that."
There is "no chance" drugs will be legalised following a report which states tougher laws have no effect on substance misuse, the government say.
A Liberal Democrat report claims it is "pointless" punishing drug users and more time should be spent on cracking down on criminal gangs who traffic drugs than addicts
But in a statement Number 10 said: "This report provides no support whatsoever for the Lib Dem's policy of decriminalisation. In fact, it clearly states that it would be inappropriate to draw those kind of conclusions.
"The Lib Dem policy would see drug dealers getting off scot-free and send an incredibly dangerous message to young people about the risks of taking drugs
"As the report makes very clear, the Government's approach already provides a good balance between enforcement and treatment, drug use is plummeting as a result and there is simply no chance that we will entertain such a reckless change of course ."
A traumatised mother has released harrowing pictures of her son lying unconscious in a hospital bed after he collapsed at a nightclub in Dartford. 18 year old Jack McEwan was taken seriously ill after drinking in the Crush Club. He believes he had his drink spiked with Ketamine, but has no idea why. Andrea Thomas reports.
A drug dealer's beginning a life sentence tonight, after mowing down a client who cheated him, with his car. The murder happened in Gillingham last January. John Ryall reports
Hampshire police have charged seven people in connection with the supply of heroin and crack cocaine.
The 18-month long investigation also found laundering of cash proceeds with the drug supplies.
The following are due in court in Southampton today on conspiracy to supply crack cocaine and heroin:
- Amarjit Dhillon, 34, of Southampton
- Mervyn Headley, 47, of Southampton
- Alizan Bockhari, 30, of Feltham
- Sandeep Panesar, 30, of Slough
- Munider Singh, 26, of Southall
- Parmjit Dhaliwal, 27, of Hayes
- Muhrukh Dogar, 28, of Slough
The investigation, named Operation Fortress, also found a well established network of organisers, financiers, couriers and street level suppliers.
A drug dealer has been jailed for three years after Kent Police officers caught him smuggling cocaine and heroin through Gillingham.
Officers noticed Dwain Heywood, who is 31-years-old, driving erratically back in April .
When he was asked to stopped, he was evasive and acting strangely, which lead to officers searching his car.
Heywood was taken back to Medway Police Station as a quantity of cash and a knife was found in the vehicle.
He was strip searched at the police station, where officers began to suspect he was hiding a quantity of drugs inside his body.
After being challenged, Heywood removed ten wraps of cocaine and four of heroin.
He was charged with possession with intent to supply a class A drug.
A man has been arrested during four drugs warrants in Kent.
Kent Police have arrested a 19-year-old man after they found white powder - thought to be cocaine or cannabis.
He was arrested on suspicion of possessing drugs with intent to supply.
The four warrants come as part of an ongoing bid to combat the supply and use of drugs in the area.
Officers searched properties in Tenterden and Kennington where they found evidence the house had been used for growing cannabis but the property had been cleared.
Cannabis was discovered at another address in Ashford.
Officers also patrolled roads after concerns raised by local residents and one driver was reported to appear at Magistrates Court after apparently driving at speeds in excess of 140-miles-per-hour on the M20.
A 42-year-old Dutch man has been charged with drug smuggling after Border Force officers at the Channel Tunnel entrance in Coquelles, France seized drugs with an estimated street value in excess of £5 million.
Exact quantities are still being assessed but the haul included heroin, amphetamine and cannabis.
The drugs were discovered on Saturday when officers stopped and searched a Dutch-registered lorry. The drugs were found in brown cardboard boxes within the vehicle’s load of empty plastic containers.
Hendrik DEKKER, from Nijkerk, Netherlands, appeared at Folkestone Magistrates Court yesterday, charged with the importation.
He pleaded not guilty and was remanded in custody.
Paul Morgan, Director of Border Force South East and Europe said:
“This was an excellent seizure by our officers and it has kept a large amount of harmful drugs off our streets.
“We will continue to work hard to keep our borders safe and crack down on drug smuggling.”
A man from Kent has been jailed for seven and a half years for trying to smuggle approximately £520,000 worth of drugs into the country.
Thomas Mayes was found attempting to smuggle in around 10 kilos of amphetamine and a kilo of cocaine.
He was stopped by Border Force officers in February at Dover's Eastern docks.
When questioned, he told officers he had been to Belgium to pick up market goods for sale in the UK. Officers searched his vehicle and found the drugs under a false floor in the vehicle.
He was arrested and the investigation was passed on to the National Crime Agency.
Mayes pleaded guilty at a hearing at Canterbury Crown Court and was sentenced today.
Paul Morgan, Director of Border Force South East and Europe said, "Drug trafficking is a serious offence and those convicted will face prison sentences. Our message to those who would consider it is that it's just not worth it."
Video. A mother is launching her own war on drugs after her 15-year-old daughter died taking ecstasy. And she says she wants help from the dealer who sold it to her. Anne-Marie Cockburn from Oxford wrote a moving account of how she coped when she learned the news that her only child had died.
Penny Silvester went to meet her.