The leadership of the Northern Ireland Policing Board have requested an urgent meeting with the Chief Constable following revelations around surveillance powers.

It emerged at a hearing of the Investigatory Powers Tribunal (IPT) in London on Wednesday that police in Northern Ireland undertook six-monthly trawls of the phone data of “troublemaker” journalists to see if they were in contact with officer sources.

It came during the hearing of a case examining allegations that investigative reporters Barry McCaffrey and Trevor Birney were subject to unlawful covert intelligence by the police.

Evidence presented to the tribunal on Wednesday suggested that Police Service of Northern Ireland (PSNI) spying operations extended to several other reporters operating in the region.

On Wednesday the National Union of Journalists (NUJ) accused the PSNI of “shocking and despicable” behaviour, and called for the service to “come clean”.

In a statement on Thursday, the Northern Ireland Policing Board said its chairman Mukesh Sharma and vice chairman Brendan Mullan are seeking a meeting with PSNI Chief Constable Jon Boutcher.

“Following discussions around yesterday’s Investigatory Powers Tribunal, the chair and the vice chair of the board have requested an urgent meeting with the Chief Constable to seek further clarification and assurance around whether surveillance powers have been used lawfully, proportionately and appropriately in the past,” the Policing Board spokesperson said.

“At the June board meeting, the board’s human rights advisor John Wadham will also provide members with an assessment on whether authorisation policies and procedures were correctly adhered to.”