The Military Reaction Force was the subject of a BBC Panorama programme last November.
Former members said the unit had shot people who may have been unarmed.
The PSNI investigation has found none of the men featured "admitted any criminal act or being involved in any of the incidents portrayed".
In a statement,  the PSNI said: "Detectives from Serious Crime Branch have studied the contents of a BBC Panorama programme broadcast last year into the activities of the MRF.
"Although there does not appear to be any admission to criminality by individuals featured in the programme, it will form part of an HET review into all deaths linked to soldiers.
"This review will begin when HET resumes its work in the near future."
The unit was disbanded in 1973, after 18 months.
The plain-clothes soldiers carried out round-the-clock patrols in Belfast in unmarked cars.
Three former members of the unit talked to Panorama. They said they had been tasked with "hunting down" IRA members in Belfast.
When asked if on occasion the MRF would make an assumption that someone had a weapon, even if they could not see one, one of the former soldiers replied "occasionally".
"We didn't go around town blasting, shooting all over the place like you see on the TV, we were going down there and finding, looking for our targets, finding them and taking them down," he said.
"We may not have seen a weapon, but there more than likely would have been weapons there in a vigilante patrol."
One of the soldiers said they were "not there to act like an army unit, we were there to act like a terror group".
Solicitor Padraig Ã“ Muirigh represents families who believe their relatives were killed by the MRF.
He said police should further investigate the soldiers' claims.
"They very openly and brazenly admitted that they were in a terror gang, that they acted outside the rule of law, that they also acted outside of the yellow card rule," he said.
"They also admitted being involved in fatal incidents in which people may not have been armed.
"I think all of that and that very high-profile Panorama programme pointed in the direction that there should have been further investigation of these matters.
"Unfortunately it appears that the PSNI have not done that, despite the request from the director of public prosecutions."
Families of people allegedly killed by an Army undercover unit have been told former members of the unit who appeared on TV admitted no crimes.