Actor Thomas Lawinky was at the centre of the 'dead swan' incident
A German actor has quit a play after throwing a fake bird at a critic who was watching the performance.
The staging of Ionesco's The Killing Game saw actors interact with the audience members.
Critic Gerhard Stadelmaier said he was sworn at by actor Thomas Lawinky when the bird was thrown at him.
Newspapers in Germany reported that a fake swan was thrown but a spokesman for Frankfurt's Schauspiel Theatre told the BBC that a rubber chicken was used.
The actor later offered his resignation while other actors have expressed their support for the performer.
The Times newspaper in London reported that a dead swan was thrown at the critic.
Mr Stadelmaier, who writes for newspaper Frankfurter Allgemeine Zeitung, told the paper: "I've never felt so humiliated in all my life".
He said that Lawinky tore his notebook from his hands.
"Nothing like this has ever happened in the theatre. Never in the 30 years of my career as a theatre critic have I felt so besmirched, so abased and so insulted," he said.
The performance included an actress playing a pregnant woman who simulated breaking of her waters.
Mr Stadelmaier has been a well-known theatre reviewer in Germany for 30 years and is known to dislike such productions.
He has been critical of the Schauspiel in the past, which has a reputation for staging violent, gory productions.
"Never have I felt such deep sorrow about the state of the theatre," Mr Stadelmaier told Frankfurter Allgemeine after the incident.
"It is robbing us of our imaginations. When blood is called for , you don't have to squirt syrup. Sex and desire do not have to be made flesh," he added.
The Schauspiel Theatre said they would "not accept that such a regrettable incident is used to restrict the theatre and its artistic freedoms".
They added that the play would continue, while they would consult with the public about the nature of their work.