Berlin police said Friday they were investigating Pink Floyd co-founder Roger Waters for incitement to hatred after he donned a Nazi-style uniform at a concert in the German capital.
Images on social media showed Waters wearing a long, black coat with red armbands on stage at the Mercedes-Benz arena last week.
"We are investigating on suspicion of incitement to public hatred because the clothing worn on stage could be used to used to glorify or justify Nazi rule, thereby disturbing the public peace," police spokesman Martin Halweg told AFP, confirming an earlier report by Jewish News.
"The clothing resembles the clothing of an SS officer," Halweg added.
Waters is a well-known pro-Palestinian activist who has been accused of holding anti-Jewish views. He has floated an inflatable pig emblazoned with the Star of David at his concerts.
Waters has played in several German cities in recent weeks as part of his "This Is Not A Drill" tour.
But it has been hugely controversial with some city officials even trying, unsuccessfully, to ban him from performing.
The Another Brick In The Wall singer denies the anti-Semitism accusations, saying he was protesting against Israeli policies and not the Jewish people.
At the same Berlin concert, Waters also flashed the names of several deceased people on a large screen, including that of Anne Frank, the Jewish teenager who died in a Nazi concentration camp.
Also named was slain Palestinian-American journalist Shireen Abu Akleh, prompting criticism that Waters was relativising the Holocaust.
"Good morning to everyone but Roger Waters who spent the evening in Berlin (Yes Berlin) desecrating the memory of Anne Frank and the 6 million Jews murdered in the Holocaust," Israel's foreign ministry tweeted earlier this week.
Waters is due to play his final German concert in the western city of Frankfurt on Sunday evening, and protesters are planning to demonstrate outside the venue.
Frankfurt city authorities sought to stop the concert but a court ruled against them, citing artistic freedom.
Uwe Becker, the anti-Semitism commissioner for the regional state of Hesse, told the Frankfurter Rundschau daily that Waters was promoting "hatred and incitement against Israel" with his shows.