The eldest son of Adolf Hitler's secretary, Martin Bormann, was yesterday accused of subjecting a former pupil at an Austrian Catholic boarding school to violent and protracted sexual abuse during his time there working as a priest and schoolmaster, more than 50 years ago.

Martin Bormann Jnr, the 80-year-old son of one of the Nazi leader's most important deputies, is renowned in Germany and Austria for his attempts to atone for his father's crimes. He has been a Catholic missionary, priest and a speaker against the Holocaust in schools.

Yesterday, however, the son of one Hitler's closest advisers faced serious allegations that he had assaulted pupils both violently and sexually while employed as a schoolmaster at an elite boarding school at the Hearts of Jesus monastery in Salzburg during the 1960s. Bormann is reported to have denied knowledge of the events.

The accusations, which were the latest in a flood of sex-abuse allegations against the Catholic church which began surfacing in Germany and Austria early last year, were made by a 63-year-old former pupil at the monastery school, named only as Victor M.

He told Austria's Profil magazine that when he was a 12-year-old pupil, Mr Bormann, who was a 30-year-old priest at the time, had repeatedly raped him and had warned him that informing others of his experiences, even his own mother, would be useless because "nobody will believe you". Three other pupils at the school told the magazine that Mr Bormann had also beaten boys so badly that they ended up covered in blood.

In one case, it was claimed, a boy was beaten unconscious. Victor M's lawyer told Profil that her client's life had been "ruined" by his school experiences and that he had had to undergo protracted psychiatric treatment as a result.

Mr Bormann spent his childhood and adolescence largely in the company of the Nazi bigwigs who were contemporaries of his father, who was once thought of as a future Nazi leader himself.

His first confrontation with the brutality of the Third Reich came as a child when he saw a chair – belonging to the Gestapo chief Heinrich Himmler – which was made out of human bones. Mr Bormann's father, who was killed by shellfire outside Hitler's Berlin bunker, was tried in absentia at Nuremberg after the war and sentenced to death, due to a lack of physical evidence about his demise.

Mr Bormann was shocked by the scale of the Nazis' crimes after the war and decided to become a Catholic priest. He served as a missionary in the Congo and wrote an autobiography in an attempt to come to terms with his Nazi past.

Later he left the priesthood in order to marry a nun who nursed him after he suffered a near-fatal injury in 1969. However, he continued to visit schools and speak out against the crimes of the Holocaust. He also met with survivors in Israel. He currently lives in Germany with his wife.