Sir Ian McKellen has been rushed to hospital after falling off stage

The audience was evacuated from the theatre and the show was subsequently cancelled.

One audience member told the BBC that the incident was "very shocking".

Sandro Trapani added: "I really hope that he is going to be alright. As far as I saw, he was conscious because he was asking for assistance."

McKellen - who plays John Falstaff in the production - was in the midst of a fight scene when the incident occurred.

The veteran actor cried out in pain after he fell off stage and theatre staff rushed to help him.

'Player Kings' began its 12-week West End run in April, and McKellen previously admitted that he was relishing the opportunity.

He told the BBC earlier this year: "Actors who have taken on the role say it is verbally very challenging - it seems that the role was written for a particular actor and comedian in Shakespeare's time, so it's a bit like being given a script for Michael McIntyre."

The production was due to move to Bristol, Birmingham, Norwich and Newcastle in the coming months, and McKellen was looking forward to touring the country.

He said: "The play itself has so many settings across England, from the taverns of the East End to the rural peaceful countryside of Gloucestershire and so it only makes sense that we take this show all around, giving the opportunity to as many people as possible to see it."