Robert Downey Jr says he would be keen to appear in Doctor Who if he was invited.

The Iron Man star took part in a Reddit Ask Me Anything online question and answer session to promote his new film The Judge, and was asked if he would ever take on the role of the Time Lord.

Robert replied: “It’s funny you’d bring that up. A writer asked me to watch a particular episode about a month ago, in hopes of helping us break story on a project. An incredible series. Anything’s possible.”

The Avengers star – who played Sherlock Holmes in Guy Ritchie’s big-screen adaptations of the famous detective – also confessed to having ‘screen envy’ of Benedict Cumberbatch’s performance in the TV series Sherlock.

Asked what he thought about the UK show, Robert said: “Very impressed with Benedict. Such smart writing on that show. I have screen envy.”