Robert Downey Jr stormed out of an interview after being questioned over his prison time

While the 50-year-old actor appeared to be in high spirits at the start of the chat the atmosphere soon stiffened when Krishnan asked him to explain a statement he made five years ago to the New York Times newspaper referencing his time in prison.

Asked to explain his words: "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 replied: "I could pick that apart for two hours and be no closer to the truth than giving you some half-arsed answer right now. I couldn't even tell you what a liberal is."

The star then became visibly upset when Krishnan continued to probe his relationship with his father and compared him to US television journalist Diane Sawyer, who is known for her pushy interview technique.

When Krishnan posed a question about Robert Downey Sr, the star had clearly had enough of his difficult line of questioning.

Getting up to leave the room, he said: "'I'm sorry, I really don't... what are we doing?

"It's all getting a bit Diane Sawyer."

The intrusive interview was later posted by Krishnan onto his Twitter account with the caption 'A Steely moment from Ironman' where he was slammed by some users for having "no class".

One tweeted: "God, Krish you can be an a**. When your interviewee is uncomfortable, don't keep pressing them. Props to RDJ for ending it."

Another wrote: "No class at all."