In the 1990s Portugal had a major heroin problem, and when it came to people injecting drugs it had one of the highest rates of HIV infection in the EU. It took a radical approach and decriminalised all personal drug use.

The law introduced in 2001 means people carrying drugs for personal consumption aren’t prosecuted - instead they are referred to health and social services to receive treatment, and the focus is on harm reduction.

And the strategy worked. The number of people using drugs fell dramatically, new HIV and Hepatitis C infections dropped and drug-related crime became much less of a problem.

So why haven’t more countries followed their lead and adopted this model?

Produced by Hannah McNeish for BBC World Service

(Photo Credit: Getty Images)