Davina Mccall hasn't ignored her dark past involving drugs and alcohol.

The TV presenter has openly admitted to that she was once addicted to the class A drug heroin.

Davina began taking illegal substances in her late-teens and by her mid-20's she was hooked.

But in order for the 46 year-old never to relapse, she takes every precaution necessary.

Davina recently gave a candid interview with The Guardian, opening up about her history of drug abuse and why she has to stay away from alcohol.

Davina recalled to the newspaper how she became an addict, "Drink and drugs helped me feel glacially cool. Drugs helped me stop feeling so insecure about what people thought about me," she continued. "And I really cared what people thought."

At first, the former 'Big Brother' presenter would only take party drugs, but before long, "heroin was my drug of choice. Heroin makes you forget everything, no problems, no worries, no anything."

However, even though she has been sober for many years, Davina still feels she is likely to relapse if alcohol was involved.

"Alcohol just leads me to drugs, because my willpower completely goes out the window..." she said. "If I'm drunk, I'd be thinking, I wonder if I could just go and hang out, and if somebody asks me or invites me in, then I'm powerless and I should just say yes."

While other recovering addicts are able to drink and manage to stay away from drugs, Davina knows she isn't one of them.

"Some people maybe can start drinking again, but I just know that I can't," she admitted.

The presenter, and fitness fanatic, has just finished a Sports Relief challenge in which she ran, swam and cycled 500 miles, from Edinburgh all the way to London, raising more than £760,000 for the charity.

Davina McCall
McCall after completing her Sports Relief Challenge