by Q Radio News
There are concerns the confidentiality of sources linked to a documentary on the Loughinisland Massacre could be put at risk.
It comes as detectives question two investigative journalists, over claims files linked to the atrocity were stolen from the police watchdog.
Trevor Birney and Barry McCaffrey worked on the documentary 'No Stone Unturned' about the murders in 1994.
Seamus Dooley from the National Union of Journalist (NUJ) has called their arrests "gravely concerning" and "disturbing":
Mr Dooley also says if there is a court action, the journalists will be supported by the NUJ to "demand that their right to protect sources of information are protected".
Meanwhile, Ulster Unionist representative Alan Lewis has welcomed the arrest of the two journalists and the police investigation: