New Zealand legal high manufacturer explains regulation

There has been a "dynamic and unprecedented global expansion" in the popularity of so-called "legal highs," according to the United Nations.

The UN's Office on Drugs and Crime said the synthetic drugs were now more popular with young people than some traditional drugs, despite claiming 68 lives in the UK in 2012.

Matt Bowden manufacturers legal highs in New Zealand, where the industry is regulated and the drugs go through similar trials to new medicines.

He told BBC Radio 5 live's Shelagh Fogarty that young people would "trend towards" regulated, synthetic drugs because they gave consistent effects "without the risk of criminal charges."