Relatives of those killed on Bloody Sunday have begun a fresh legal challenge to a decision allowing police officers to give evidence behind screens to the Saville Inquiry.
Twenty serving and former police officers have won the right to give their evidence from behind screens after arguing they could be in danger if their identities were revealed.
Lawyers acting for the families went to the Court of Appeal in Belfast today, saying people attending the inquiry should be able to see the demeanour of those testifying.
The case has been taken in the name of Ms Mary Doherty, whose brother Gerard Doherty (17) was one of 13 civilians shot dead when paratroopers opened fire on a civil rights march in Derry on January 31st, 1972.
Mr Seamus Treacy QC, for Ms Doherty, said a large number of police officers due to have given evidence to the tribunal in February suddenly gave notice that they wanted to be screened from view while giving evidence.
He said Ms Doherty, who had attended the Saville Inquiry every day, wanted both to see and hear what members of the security forces had to say. Her brother had been found with a nail bomb in his pocket and she believed it was planted on him, he said.
Mr Treacy said it was particularly frustrating to the families that screening had been introduced because the British Prime Minister had said when setting up the inquiry that it would be "open and transparent".
Last week, the "Real IRA" said it posed no threat to any witnesses giving evidence to the Saville Inquiry. Allegations that security force witnesses were at risk was a "smokescreen aimed at hiding the truth", it said.
PA