The Moulin Rouge! actress, who plays scientist Rosalind Franklin in the production, was approaching the final half hour of the play when Attenborough, the grandson of late actor/director Richard Attenborough, passed out.

Kidman and her male co-stars rushed to his aid and an ambulance was called to the Noel Coward Theatre.

The theatre manager came onstage to announce a 15-minute break, and the performance later resumed with Attenborough's understudy.

Further details of Attenborough's condition had not been revealed as WENN went to press.