The onus is on the state to provide an alternative to Northern Ireland's Historical Enquiries Team (HET) which avoids its predecessor's mistakes, an independent expert said.
Professor Bill Rolston from the University of Ulster interviewed relatives of victims from across the political spectrum as part of one of the largest studies yet undertaken of their attitudes towards the controversial group of detectives. Three quarters of those surveyed felt the HET should be disbanded.
The future of the organisation established to investigate more than 3,000 unresolved Troubles killings is being considered by PSNI Chief Constable Matt Baggott. An inspectorate has found that it scrutinised cases where the state was involved with less rigour than others.
Prof Rolston's report said: "The onus is on the state to provide an alternative to the HET which avoids its mistakes and gives relatives of victims what the HET seemed to promise - investigation, disclosure, support, information and perhaps even some sense of closure and justice."
The research recognised problems the HET faced in revisiting the past, including challenges posed by the passage of time.
To conduct his research Prof Rolston sought the help of a range of victims' groups and lawyers working in the area, including West Belfast-based Relatives for Justice and largely Protestant victims campaigners Families Acting for Innocent Relatives (FAIR). He interviewed families of Catholic and Protestant, IRA and Sinn Fein, UDR and RUC victims as well as those whose loved ones belonged to loyalist paramilitaries or the British army.
The report noted complexity in the results and other factors but concluded categorically that there is a profound dissatisfaction with the experience of dealing with the HET.
"This dissatisfaction is not confined to one category of victim but goes right across the board. The basis of that dissatisfaction rests on three main elements: interaction, the final report, and the gap between expectations and results," it said.
Only 12% of bereaved family members interviewed were totally glad they had worked with detectives and 41% said they were definitely not, the study added.
Inadequate final reports and difficulty in obtaining information from the independent group of officers investigating more than 3,000 unresolved deaths during the conflict were among claims made by victims' families.