Madonna has started hiding her face behind a mask in interviews if she's quizzed on a topic she'd rather not discuss.

This is going to be a sign that I don't want to answer the question

The pop superstar told U.S. talk show host Ellen DeGeneres she'd hold the mask in front of her face "if you ask me a question that I feel uncomfortable with" during a taped chat earlier this week.

The Papa Don't Preach singer added, "This is going to be a sign that I don't want to answer the question".

DeGeneres responded by joking, "You could just say, 'I feel uncomfortable with that question', and not answer it. You can just tell me that".

Madonna said, "But this is more theatrical".

The full interview airs on Monday.