At least 547 boys at a German Catholic choir school fell victim to sexual and physical abuse in what some later compared to "prison, hell or a concentration camp", an investigator's report said Tuesday.

In his final report on abuses at the Regensburger Domspatzen cathedral choir school between 1945 and the early 1990s, lawyer Ulrich Weber said he had uncovered 67 cases of sexual abuse and 500 cases of other physical violence -- with some former singers having suffered both.