UK prosecutors Tuesday said they would appeal a court's decision to drop a charge of supporting "terrorism" brought against a Northern Irish singer from punk rap group Kneecap.

"We are appealing the decision to dismiss this case as we believe there is an important point of law which needs to be clarified," a Crown Prosecution Service spokesperson said, referring to the case against Liam O'Hanna, also known by his stage name Mo Chara.

O'Hanna, 27, had been charged under Britain's terrorism laws for allegedly displaying a flag belonging to the banned Lebanese group Hezbollah during a concert in November 2024.

But the case was thrown out by a London court last month after a judge found there had been a technical error in the way the charge had been brought.

Kneecap said the decision to appeal was "unsurprising" and called it a "waste of taxpayers money" in a statement posted on social media, repeating claims that the case was a "witch-hunt against Palestinian solidarity".

"We will fight you in your court again. We will win again," the group added.

O'Hanna, named Liam Og O Hannaidh in Irish, was charged in May when a video emerged from a November concert in London in which he allegedly displayed the Hezbollah flag, an offence the singer has denied.

But chief magistrate Paul Goldspring found the charge was not brought by prosecutors within the legal time limit, rendering it "unlawful and null".

The band, which sings in Irish and regularly leads chants in support of Gaza during performances, has had multiple concerts cancelled internationally over its pro-Palestinian stance and other controversies.

Canada last month barred Kneecap from entering the country, citing the group's alleged support for Hezbollah and Palestinian militant group Hamas.

But its performance in Paris went ahead in September despite objections from French Jewish groups and government officials. The group also played the vaunted Glastonbury Festival in southwest England in June.