WARSAW, Poland (AP) — British historian David Irving, who once served prison time in Austria after being convicted of denying the Holocaust, says he is leading a tour of former Nazi death camps in Poland because people want to hear his view.

Irving told The Associated Press Thursday he does not deny millions of Jews were killed by the Nazis but is not afraid to ask "difficult questions" about the Holocaust. He has previously argued many died through disease rather than execution.

His group, including Britons, Americans and Germans, has visited Treblinka and plans to visit three other former death camps before heading home Sept. 30. He would not say how many are in the group nor how much they paid.

Polish authorities say Irving will be prosecuted if he violates the country's law forbidding Holocaust denial.