Media watchdog Ofcom is investigating Channel 4's The Kevin Bishop Show after receiving dozens of complaints about a Holocaust-themed sketch.
The two-minute skit, aired last Friday evening, was a spoof musical version of the scene in the film Sophie's Choice in which the heroine is forced to choose which of her two children to keep with her at Auschwitz.
Billed satirically as "a unique interactive theatre experience," it featured Mr Bishop as one of three men dressed as SS officers.
One of the guards sang: "I will let you choose which one to lose, your son or your daughter."
A voiceover informed the audience that this was a "nightly interactive vote [where] every evening you can help make Sophie's choice for her".
The audience then used keypads to vote for whether she should hand over her son or daughter.
The sketch has caused controversy with both Ofcom and Channel 4 receiving complaints.
Lord Janner, chairman of the Holocaust Education Trust, called it "distasteful, disgusting and unpleasant".
But Channel 4 defended its decision to broadcast the sketch. A spokesman said: "The Kevin Bishop Show is a comedy programme that takes a humorous look at many aspects of the entertainment world. The sketch intended to satirise the increasing demand for audience interaction in popular culture and the publicity-grabbing themes of modern musicals.
"We believe Channel 4's Friday night audience would understand this was the intention of the joke."
He confirmed that the channel had received "a number of complaints" but was not prepared to say how many.
A spokeswoman for Ofcom said: "We have had 27 complaints so far. We are looking into it and will publish anything we need to."
Voiceover - "A film classic is finally brought to life in London's West End. The Daily Mail calls it ‘a masterpiece'. The Telegraph says ‘about time' and the Jewish Chronicle says ‘way too soon'. Get ready for Sophie's Choice, The Musical."
Guard (sings) - "I shall let you choose which one to lose. Your son or your daughter."
Sophie (sings) - "Don't make me choose. I can't bear to lose my son or my daughter."
Three guards (sing) - "You must choose, you must choose, you must choose which one to lose."
Sophie - "Then you must help me choose."
Voiceover - "Featuring a unique nightly interactive vote every evening, you can help make Sophie's choice for her."
Shouts from audience - "Take the daughter."
Sophie (sings) - "Very well, take my daughter."
[Daughter is led off the set by a guard with a gun]
Voiceover - "Sophie's Choice The Musical, a unique interactive theatre experience. Coming soon to the West End."