Robert Downey Jr. cut short an interview with British TV journalist Krishnan Guru-Murthy this week when he attempted to ask the Iron Man star about his "dark periods." The seven-minute interview started to go downhill around the five minute mark when Robert was quizzed about his history of drug abuse and the time he spent in prison.

Robert, 50, was in London to promote his new film Avengers: Age of Ultron. He was his usual charming self throughout the exchange, until asked to explain a comment he made to the New York Times in 2008, in which he said, "You can't go from a $2,000-a-night suite at La Mirage to a penitentiary and really understand it and come out a liberal."

Robert Downey Jr. cut short his interview with Krishnan Guru-Murthy Photo: Channel 4

Looking a little baffled by the question, Robert politely responded with a smile, "I could pick that apart for two hours and be no closer to the truth... I couldn't even really tell you what a liberal is, so therein lies the answer to your question."

The Channel 4 reporter persisted, and then asked the star whether it meant that when he left prison more than ten years ago, he came out a liberal. "Umm, are we promoting a movie?" responded the married father-of-three, who has famously turned his life around following his conviction and after undergoing rehab, before explaining the quote was simply how he felt on that particular day.

Robert Downey Jr. stormed out of his interview Photo: Channel 4

It was the interviewer's next question about Robert’s relationship with his father that broke the camel's back. Before he could finish, Robert had stood up and started to remove his microphone, with the interviewer apologizing for upsetting him. "You seem OK, it was just getting a little Diane Sawyer and you're kind of a schmuck," Robert said before leaving the room.

Robert has been very open about his troubled past saying that he and longtime girlfriend Sarah Jessica Parker and his wife of 9 years Deborah Falconer both left because of his drug addiction. He has since married producer Susan Levine, whom he credits for helping him stay sober, and had two children with her.

Robert credited his wife Susan for helping him stay sober Photo: Getty Images

Unfortunately, the actor's drug issues aren't behind him quite yet; his son Indio Falconer from his first marriage was arrested in 2014 for felony possession of cocaine. The star has yet again publicly discussed this private battle saying, "Unfortunately there's a genetic component to addiction and Indio has likely inherited it. Also, there is a lot of family support and understanding, and we're all determined to rally behind him and help him become the man he's capable of being. We're grateful to the Sheriff's department for their intervention, and believe Indio can be another recovery success story instead of a cautionary tale."

Krishnan Guru-Murthy attempted to ask the star about his "dark periods" Photo: Channel 4

When it came to the awkward interview Robert made no mention of the incident, but Krishnan later tweeted a photo taken during the interview, with the caption, "Oh dear. Abrupt end to our Robert Downey Jr interview when we started talking about jail and drugs." He later shared a link to a video of the interview, writing, "A steely moment from Ironman."

It's not the first time the TV journalist has upset a celebrity interviewee. In 2013, he clashed with Quentin Tarantino after quizzing him about whether there's a link between "enjoying movie violence and enjoying real violence."

Watch the clip of Robert Downey Jr walking out below:

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