Rapper slowthai was forced to explain the meaning behind a controversial T-shirt worn during his performance at last weekend's Osheaga Music and Arts Festival in Montreal.

The 27-year-old Brit took to the stage Saturday in a shirt depicting the word 'DESTROY' with a swastika underneath.

"I'm sorry to anyone who is offended by me wearing an anti-fascist/anti-regime T-shirt and the use of the symbol it represents," he tweeted. "I want you to know I stand firmly against anti-Semitism and fascism of any kind."

Osheaga organizers also took to social media Monday to address the issue, which caused much confusion among festivalgoers.

"We sincerely apologize to anyone who may have misinterpreted this message and felt hurt," they stated.

The T-shirt is a version of a design by renowned English designer Vivienne Westwood in partnership with Malcolm McLaren in the mid-1970s.

The original creation depicts a pink Nazi swastika in a red circle, an inverted image of Jesus on the cross and a postage stamp image of Queen Elizabeth under the word DESTROY.

It is often considered one of Westwood's most controversial designs and has been worn by Rolling Stones' lead singer Mick Jagger and British singer-songwriter Johnny Rotten.

Nevertheless, the Centre for Israel and Jewish Affairs (CIJA) points out the symbol itself does not have a place on a musical stage.

"The swastika is forever linked with the German National Socialist project to literally exterminate and erase the Jewish people," the centre wrote in a letter to the rapper. "It is a symbol synonymous with anti-Semitism, a hatred that occupies a unique status in history with its culmination being the Holocaust."

CIJA argues, "Nazi imagery is not a fashion statement. It should not be used as a stunt for attention or as a vehicle for publicity."

The centre also wrote to Osheaga co-founder Nick Farkas to express its concerns, asking that he ensure "it doesn't happen in your events again."