Laverty, who has won the Palme d’Or for his collaborations with director Ken Loach, was detained by officers in Edinburgh on Monday.

It is understood that Laverty faces a terrorism charge for wearing a T-shirt stating: “Genocide in Palestine time to take action”.

In other cases, the garment has been alleged to be in support of Palestine Action, a protest group proscribed as a terrorist organisation by the Labour Government in July.

One witness told The National that Laverty had been arrested in the Summerhall courtyard, with officers allegedly instructing people to delete video of the incident or face terror charges.

READ MORE: Police Scotland ‘breaching human rights to subdue Palestine protests’, activists say

The Scottish Palestine Solidarity Campaign, which produced the T-shirt, said Laverty had been taken to the police station on St Leonards Street and that activists would be heading down as well to show support.

Police Scotland has been approached for comment.

Laverty has been wearing the allegedly offending T-shirt across his appearances at the Edinburgh festivals.

Last week, he and Loach joined a demonstration against the proscription of Palestine Action.

Ken Loach and Paul Laverty pictured at a demonstration earlier in August (Image: NQ) On Monday, Laverty had been among the pro-Palestine activists to turn out in support of Moira McFarlane, who has been charged under terror laws for wearing the T-shirt.

Earlier this month, the Scottish Human Rights Commission (SHRC) warned that policing of Palestine protests risked infringing on people’s right to freedom of expression and assembly.

The UN’s human rights chief, Volker Turk, has warned that Labour’s proscription of Palestine Action puts the UK “at odds” with international law.

Irish author Sally Rooney has said she will continue to support the group, leading to a terror warning from the UK Government.