The families of the six men killed in the Loughinisland massacre are to hold a vigil outside the Heights Bar in protest after two journalists were arrested over suspected theft of documents from Police Ombudsman's office.
Journalists Trevor Birney and Barry McCaffrey were arrested by detectives from the Durham Constabulary on Friday morning in connection with the suspected theft of confidential documents held by the Police Ombudsman of Northern Ireland relating to the Loughinisland massacre.
The documents were used in the documentary No Stone Unturned which looked into the 1994 killings.
Officials from the Ombudsman office had reported the theft to PSNI, who in turn asked Durham Constabulary to conduct an independent investigation. The arrests of the men, who were both key players in the making of the documentary, were made in Belfast.
Spokeswoman for the Loughinisland families, Clare Rogan, expressed anger at the arrests and said a protest will be held outside the Heights Bar in Loughinisland on Friday evening.
"We are shocked and appalled at the arrest of two journalists related to the 'No Stone Unturned' documentary, which exposed the extent of state collusion between the state and loyalist paramilitaries in Loughinisland,' she said.
"The British Government have systematically denied and continue to cover up its role in the murder of six people in the Heights Bar.
"Today's arrests show the lengths of desperation that the British Government and state forces are prepared to go to, in order to stifle the truth about what happened in Loughinisland.
"The Police Ombudsman's report into Loughinisland murders was one of the most damning expositions of state collusion in mass murder ever published.
"Our families and many other families across the island, some of whom have been denied the basic right to an inquest, have campaigned for many years against state collusion and for truth and justice for our loved ones.
"These actions are the latest attempt to deter the work of families and journalists who seek to shine the light on the dark levels of collusion at the heart of the British state."
The families are planning a vigil outside the Heights Bar in Loughinisland on Friday evening to protest at the development.
Mr Birney and award-winning documentary maker Alex Gibney.
Former Andersonstown News and Irish News reporter, Barry McCaffrey, 48, has been researching the Loughinisland atrocity for more than 10 years, and has been a fixture in Irish media for over two decades.
Some of Mr McCaffrey's most prominent work was related to the 2004 Northern Bank heist in Belfast.
Mr McCaffrey previously worked for The Detail, an investigative news website which has carried a number of stories regarding Loughinisland, as well as a number of other investigations.
Mr McCaffrey was awarded the overall justice media award in the Attorney General's Justice Media Awards in 2013.
The award recognised his investigation into the use of solitary confinement in Northern Ireland's prisons.
In the same year, Mr McCaffrey was named digital journalist of the year.
The searches linked to Friday's arrests have been carried out at Upper Arthur Street where The Detail news website and Fine Point Films are based.
The award-winning producer and director Mr Birney, 51, founded Fine Point after 20 years working in the media.
Mr Birney began his career in Enniskillen on the Impartial Reporter newspaper and has also worked in radio.
Since then, he has produced a number of documentaries and series for Irish, UK and international broadcasters.
He was a co-producer on the Oscar-shortlisted, Alex Gibney feature-documentary, Mea Maxima Culpa: Silence In The House Of God, for which he received an IFTA in February, 2013.
He was nominated for an Emmy for his feature documentary, Elian, produced by Belfast-based Fine Point.
In 2006, Mr Birney founded Belfast-based production company Below The Radar where he produced a range of English and Irish language programmes, including political biographies and historical documentaries.
He is the former editor of current affairs at Ulster Television.
He has also won a justice media award, two Royal Television Society awards, been nominated for three others and was named NI Broadcaster of the Year in 2002.
Police say the material had been in the possession of the Police Ombudsman for Northern Ireland.
The two men were arrested by officers from the Durham force.
A number of documents and computer equipment seized during the raids will be examined by specialist officers.
A spokesman for Durham Constabulary described the investigation as "complex".
Six people were killed on June 18 1994 when loyalist gunmen burst into a bar in Loughinisland, Co Down, and opened fire on customers.