A former addict whose casual use of cannabis as a teenager spiralled into years of crack cocaine and heroin addiction says schools need to do more to make young people aware of the dangers of drugs.

Paul Hannaford has been clean for more than six years and for the past four years has spoken to some 200,000 people about his past.

“I went into a youth club four years ago and gave a talk.

“Now I work all over the country. I just wanted to give something back to the community I had nearly destroyed,” he said.

The 44-year-old’s life today is a far cry from the two decades spent with a fully fledged addiction to hard drugs, needing to inject himself up to 50 times a day.

To fund his habit, Paul turned to crime and was in and out of prison 15 times.

It was when lying in hospital with doctors wanting to amputate his badly infected legs that Paul decided to make rehab work for him.

On Thursday, he visited Jo Richardson Community School in Dagenham to tell Year Ten pupils his harrowing story.

“My talk is brutal, it’s really upsetting. There are shocking images of my legs when I was in hospital. But it has to be hard-hitting. I’m there to make a difference,” he said.

Paul, from Romford, was 13 when he got hooked on cannabis and believes that drug education in schools needs to start earlier.

“Cannabis and ketamine are a large part of young children’s lives.

“It starts about Year Nine or Ten because schools don’t bother getting them educated. I’m saying get them early enough. It is about the choices they are going to make over the next few years.”

He said many schools are wary about how disturbing his story is, which prevents children hearing a real account of drugs.

“They are putting the school’s reputation before the health of their pupils,” he said.

Donna Hector, head of personal development education at Jo Richardson, said: “Through word of mouth I heard that Paul Hannaford sessions were hard hitting and get students to really think about choices and consequences. This seemed ideal for our year 10 students to be a part of.”

Feedback from the pupils was full of admiration for Paul.

One tweeted: “I’ve heard a lot of stories about drugs and gangs but yours today was the one that will wake anyone up, so much respect.”