The NGO alleges that gardaí adopted a “heavy-handed policing approach” to a group of protesters who marched to block a road to Dublin Port on 4 October.

ICCL says this included the indiscriminate use of pepper spray without verbal warning and batons, and led to a number of reported injuries, including a broken wrist.

It also said it is concerned about the treatment of individuals when they were arrested, with reports that one protester was subject to mistreatment.

In a statement, ICCL said: “ICCL and the University of Galway have created a network of trained, independent legal observers.

“On Saturday legal observers monitored and documented the policing response to the protest in Dublin Port. In the course of their work, they were also affected by the pepper spray.

“Legal observers are independent observers and recognised internationally as human rights defenders. Gardaí are obligated to ensure they can carry out their work.

“As co-conveners of the Irish Network of Legal Observers, ICCL and the University of Galway are compiling reports and footage from the protest.

“In the coming days, we will share our findings and concerns with the Garda commissioner and publish a report on this incident.”