The former chief justice of South Africa has called on the British government to address "real and substantial" grievances of families of those killed unlawfully and who want to uncover the truth.
Justice Arthur Chaskalson made his appeal in Belfast yesterday following a three-day visit to examine the effects of anti-terrorism legislation for the Swiss-based International Commission of Jurists, of which he is president.
Referring to the Inquiries Act, which governs the holding of inquiries into the murder of Pat Finucane and other controversial killings where collusion with paramilitaries is alleged, Justice Chaskalson said the legislation gave "power to the executive to control the flow of information".
The Act brought into question the independence of inquiries. This had added to the suffering of relatives who had struggled for years to uncover the truth.
"It does seem to me that where people are struggling to find out what happened, it is very important that the inquiry should not only be open and independent, but perceived to be open and independent," he said. "It should be transparent."
The Inquiries Act allows the British government conduct elements of inquiries in secret and to redact the written findings.
Referring to the relatives of those murdered, he said: "They have suffered much anguish as a result of a failure to do so. The panellists urge the authorities to address this real and substantial grievance.
"The vesting in security forces of wide and discretionary powers which are not subject to strict control can easily lead to abuse, and this has in fact happened in Northern Ireland."
Justice Chaskalson had been joined in Northern Ireland by Justice Paul Zaffaroni of the Argentinian Supreme Court as they collected evidence from academics, politicians, police and legal figures. They are due to visit Britain next week where they will have talks with British ministers, Amnesty International and others.
The jurists' comments were welcomed by the SDLP's Alban Maginness. "Justice Chaskalson's comments are completely correct," he said. "Any inquiry which is not open and transparent and which is not seen to be so is fundamentally flawed.
"The International Commission for Jurists is the latest in a long line of legal professionals, international pressure groups, and governments who have joined the families, the SDLP and others in calling foul on the Inquiries Act."