The authorities in Northern Ireland have failed to deal with the legacy of the past, human rights campaigners claim.
Amnesty International said it would be raising the concerns when it gives evidence to the United Nation's committee against torture in Geneva this week.
The organisation claimed existing mechanisms such as the Historical Enquiries Team (HET), the Police Ombudsman and ongoing legacy inquests had proved inadequate in securing accountability for alleged past human rights violations and abuses.
"The piecemeal nature of existing mechanisms and their narrow remits means that they are simply not able to secure full accountability for past human rights abuses.
"We are bringing our concerns to the attention of the United Nations in the hope that the international community will urge the UK authorities to ensure a new approach is found to address the outstanding abuses of Northern Ireland's past," said Patrick Corrigan, Amnesty's Northern Ireland programme director.
Part of the committee's remit is the investigation into deaths by lethal force that occurred during Northern Ireland's 40-year conflict.
UK Government representatives will be quizzed by the UN scrutiny committee on Tuesday.
Mr Corrigan said the HET and Police Ombudsman were delivering for some families, but were failing to deliver fully independent, effective, prompt and thorough investigations for others.
"A new comprehensive process is crucial to ensure accountability for those abuses, not just to help individual victims and their families, but to help society as a whole to build a shared future on firm foundations," he added.
As part of its research Amnesty said it had spoken to victims and their families over the past 12 months. The organisation said it would publish the findings before the end of the year.