Operation Ballast has investigated a number of UVF murders
A victims commissioner has claimed victims lack confidence in the transfer of Operation Ballast from the Historical Enquiries Team to police.
At the end of last year the PSNI took on the investigation into the activities of the UVF in north Belfast.
The Policing Board's human rights committee is meeting later to hear the chief constable explain the move.
Victims commissioner Brendan McAllister has asked the Policing Board for its view on the transfer.
Operation Ballast is investigating the activities of the UVF in north Belfast, primarily a unit based in the Mount Vernon estate.
The police's serious crime branch took over the investigation from the HET at the end of last year, renaming it Operation Stafford.
The original probe was set up amid claims that security force members colluded with the UVF.
Former Northern Ireland Police Ombudsman Nuala O'Loan, claimed paramilitary killers were protected from prosecution because they were police agents.
She examined the allegations after a complaint from Belfast man Raymond McCord, whose son, Raymond McCord Junior, was murdered by the UVF in 1997.
"Given the findings of Baroness O'Loan when she was Police Ombudsman - that police officers had collaborated with informers who had been involved in some of these killings - families are naturally worried at the return of the investigation to the Police" Mr McAllister said.
"The chief constable and the Policing Board need to appreciate the depth of alienation and distrust among victim families."
Meanwhile, the former chairman of the UVF-linked Progressive Unionist Party has claimed loyalists had been assured by the government that they would not be pursued for terrorist offences committed before 1998.
William "Plum" Smyth told the Belfast Telegraph that the then Secretary of State Mo Mowlam offered an implicit amnesty to all participants in the conflict at the time of the Good Friday Agreement.
The government have not yet responded to his claim.