Father Gabriele Amorth, a prominent Roman Catholic exorcist, has died aged 91.

Father Amorth who was the chief exorcist for the diocese of Rome, passed away after suffering from a pulmonary illness.

The Catholic priest controversially claimed Harry Potter books encourage children to believe in black magic and yoga is “evil” because it promotes Hinduism.

Father Amorth believed people possessed by Satan tend to vomit pieces of iron and shards of glass. He maintained both Hitler and Stalin were possessed by the Devil, but that fact didn’t excuse their abhorrent actions.

“For example, I am convinced that the Nazis were all possessed by the devil. If you think about what types like Stalin, Hitler did ... certainly they were possessed by the devil,” he said.

Born in Modena in northern Italy in 1925, Gabriel Amorth was ordained a priest in 1951. In 1985, he was appointed Exorcist of the Diocese of Rome.

During his lifetime, Father Amorth claimed to have performed 70,000 exorcisms and documented them in a number of books. The Italian news agency ANSA said Father Amorth had said he found himself faced with true demonic possession at most 100 times

He credited the 1973 film The Exorcist for giving a “substantially exact” representation of what it was like to be possessed by Satan. He did maintain the special effects were exaggerated, however.

During his exorcisms, his patients often had to be physically restrained. "From their mouths, anything can come out – pieces of iron as long as a finger, but also rose petals," he said.

His conviction in the power of exorcisms informed his approach to current affairs. In a Facebook post in 2015, he asserted: “ISIS is Satan.”

Spanish theologian Father Jose Antonio Fortea told the Catholic News Agency: “Now he rests from his many battles with the devil.”