Liam O’Hanna, a member of the Northern Irish hip-hop group Kneecap, has been charged by British police with a terrorism offense. The charge stems from an incident where he allegedly displayed a flag in support of Hezbollah, a militant movement.

Police initiated an investigation after a video surfaced in April, reportedly showing O’Hanna holding the Hezbollah flag during a concert in London last November. The counter-terrorism unit became involved following the emergence of the video.

O’Hanna is accused of displaying the flag “in such a way or under such circumstances as to give rise to a reasonable suspicion that he supports a proscribed organization,” violating British anti-terrorism laws.

Hezbollah, formed in 1982 in response to an Israeli invasion of Lebanon, is a Shia Muslim movement with a history of attacks on American targets. The group has also been an active ally of Hamas.

Kneecap maintains they do not support Hamas or Hezbollah and assert that the video has been misinterpreted. The controversy has already led to the cancellation of several of their performances.

Despite the charges, Kneecap is still scheduled to perform at the Northside festival in Aarhus this summer. O’Hanna is due to appear in court in London on June 18, just 11 days after their planned concert in Denmark.