Singer Pete Doherty has apologised for offending festival-goers in Germany when he performed a Nazi-era rendition of their national anthem.
Crowds in Munich booed the Babyshambles frontman when he sang Deutschland, Deutschland Uber Alles during a live radio broadcast on Saturday.
Doherty's manager Adrian Hunter said the singer deeply regretted any offence he might have caused.
The controversial singer's performance was cut short when he sang a version of the anthem banned after the Second World War.
The lyrics from the anthem Das Deutschlandlied translate as 'Germany above all' and were written in 1841 as a rallying call for a unified German nation, but the meaning was later hijacked by the Nazi's as a statement of racial superiority.
Doherty sang the offensive lyrics mid-way through an acoustic version of Ray Charles' song Hit The Road Jack, provoking boos and jeers from the crowd. Seemingly unaware of the hostile reaction, he repeated the lyrics twice more.
A radio station broadcasting the event live immediately cut its transmission but Doherty continued to play another five songs before organisers asked him to leave the stage.
His manager's full statement, posted on the German On3 festival organiser's website, said: "Pete wanted to celebrate his appearance in Munich by assimilating and integrating with the crowd, something he tries to do wherever he goes.
"He was unaware of the controversy surrounding the German national anthem and deeply apologises if he has caused any offence. Pete himself is from Jewish descent and has fought against racism and fascism with numerous organisations including Love Music Hate Racism. This is a subject he feels very strongly about."
He continued: "Pete Doherty therefore deeply regrets if any other band, musician, team-member, visitor or the listeners of the broadcast felt offended by his performance.
"This was not intended. Pete is an active participant in anti fascist and anti racist organisations and would like to take this opportunity to encourage anyone of any race or creed to unite and actively fight against the resurgence of the far right's hateful doctrine in any way they can."