The condition of the Italian actor Raphael left in a coma after a hanging scene went wrong during a live theatrical production is deteriorating, it has been reported.

Raphael Schumacher, 27, was appearing in a production of Mirages at the Teatro Lux in Pisa when an audience member realised he was in trouble.

Pisa Today reported the actor was not currently responding to treatment.

The newspaper added investigators were satisfied the incident was an accident.

They will now try to identify if the theatre was negligent in following safety standards.

Police launched an investigation after sealing off the theatre at the weekend, and interviewed members of the cast and audience.

It concluded the incident was an accident after speaking to the audience member - believed to be a recent medical graduate - who helped Schumacher.

The theatre-goer went to assist the actor - who was wearing a bag over his head - after seeing his body was trembling, and lowered him to the ground.

Schumacher was taken to hospital but remains in a coma.

The actor reportedly changed the ending of the scene, which was meant to involve a gun rather than see him hanging.

Previous on-stage disasters

In December 2013 the roof of the Apollo Theatre in London collapsed during a performance of The Curious Incident of the Dog in the Night Time. Seventy-six people were injured, seven of them seriously.

In December 2008 an actor in Vienna slit his throat during a suicide scene, after a blunt prop was accidentally replaced with a real knife. He missed his artery and survived, and received two stitches to the wound before coming back on stage the following night.

The Broadway musical Wicked has seen several disasters in its run: an actor broke two ribs falling through a trap door, and another actor had to cut short a flying scene when her cape got stuck in machinery.

In 1981, a 6,000 gallon tank of water burst across the stage of the National Theatre in London, flooding the machinery. Some previews were cancelled but the production of Way Upstream went ahead.

In 1937, the actor Laurence Olivier escaped injury when a heavy weight fell next to him in the wings. He was preparing for a production of Shakespeare's play Macbeth, which has long been associated with bad luck and actors' superstitions.

In 1613 the Globe Theatre in London was burnt to the ground when a spark from a cannon used in the play set fire to thatching. There were no reports of any injuries. A year later the theatre was rebuilt, only to be demolished by the Puritans on ideological grounds, decades later.