Superstar Robin Thicke has admitted to spending half a million dollars on Marijuana.

The 36-year-old Blurred Lines singer, who was arrested for possession of a small amount of cannabis in February 2012, revealed the true extent of his use of the drug during a candid interview with the Sun.

Thicke revealed that he gets a pal to prescribe him the magic medicine for a "bad knee" and that he smokes like a "non-stop chimney" when he is at home.

"I do smoke, I do everything I'm not supposed to do. Weed is my crutch, my muse, the lesser of all evil," he confessed to the publication.

He went on to confess that as result of his addiction he had "spent a good $500,000 [£320,000] on pot".

"I've tried to quit smoking. I've quit everything once," he said "My buddy runs a store. I can get medical marijuana. When I'm at home it's a non-stop chimney."

Meanwhile, Thicke was recently forced to defend his hit, Blurred Lines, which attracted criticism for its alleged "rapey" lyrics and misogynistic undertones.

In June the accompanying video, which featured a bevy of topless models draping themselves over the fully-clothed male artistes, was banned from YouTube.

In the wake of the backlash Thicke described the song as a "feminist movement".

"It's supposed to stir conversation, it's supposed to make us talk about what's important and what the relationship between men and women is, but if you listen to the lyrics it says "That man is not your maker" - it's actually a feminist movement within itself," he added.