Brussels  - British bishop Richard Williamson's comments questioning the Holocaust are "unacceptable" and an "attack on reality," the European Union's top justice official said Friday.

But the EU does not yet have concerted rules in place which would allow for his prosecution, leaving the response in the hands of individual governments, EU Justice Commissioner Jacques Barrot told journalists at a meeting of EU justice ministers in Brussels.

EU member states agreed a law criminalizing hate speech and incitement to violence in November, but "it is unfortunately too early to apply it, because it has not yet been written into national laws," Barrot said.

Some, but not all, EU member states already treat Holocaust denial as a crime.

The justice ministers of the Czech Republic and Sweden - current and future holders of the EU's rotating presidency - said that any decision to prosecute Williamson for his comments would have to come from the courts in individual member states, not politicians.

Williamson, in an interview with Swedish television last November, had said he believed that "up to 300,000 Jews perished in Nazi concentration camps but none of them in gas chambers."

"I believe there were no gas chambers during World War II," he said.

The comments sparked widespread outrage around the world, and led to the bishop's expulsion from Argentina on Tuesday. He arrived in Britain on Wednesday.

On Friday the 68-year-old published an apology on the website of the British arm of the ultra-conservative Society of Saint Pius X, of which he is a member. (dpa)