Beginning in the early 1990s Morel was investigated by authorities for war crimes and crimes against humanity, including the murder of more than 1,500 prisoners from Upper Silesia, most of from the local population. In 1996, he was indicted by Poland on charges of torture, war crimes, crimes against humanity and communist crimes. After his case was publicized by the Polish, German, British, and American media, Morel fled to Israel and was granted citizenship under the Law of Return. Poland twice requested his extradition, once in 1998 and once in 2004, but Israel refused to comply and rejected the more serious charges as being false and again rejected extradition on the grounds that the statute of limitations against Morel had run out and that Morel was in poor health. Polish authorities responded by accusing Israel of applying a double standard, and the controversy over Morel's extradition continued until his death.