Opera director Kirsten Harms found herself at the eye of a storm

Berlin's Deutsche Oper shelved performances of Mozart's Idomeneo after police advised there were a serious risks of protests.

But after an official all-clear it was rescheduled for dates in December.

Now management have admitted it cannot find Muhammad's head or those of Jesus, Buddha and Neptune which also feature.

The original decision to drop the opera, taken in the wake of the Danish Muhammad cartoons row, sparked a debate about free speech in Germany.

Deutsche Oper Berlin spokesman Alexander Busche said: "We can't find the heads at the moment, but that doesn't mean they have been stolen. We don't think that's the case,"

He added: "Either they will show up in the next few days, or we will have new ones made."

The company has insisted the performance will go ahead on the 18 December as planned with all the correct props.