SECRET interviews with Old Bailey bomber Dolours Price have been handed over to PSNI detectives.
Officers probing the death and disappearance of Belfast mother-of-10 Jean McConville, right, flew to the US for the Boston College tapes.
The PSNI confirmed two detectives from its serious crime branch travelled to Boston to take possession of materials, following authorisation from the US Supreme Court.
"The officers will return to Northern Ireland to assess the material and continue with their inquiries," a spokesman said.
Price, who died in January, gave the interviews as part of the 'Belfast Project' carried out by Boston College.
The oral history of the Troubles collected recordings with republican and loyalist paramilitaries on the condition that confidentiality would be guaranteed until after their deaths.
Price has clashed with Sinn Fein leader Gerry Adams in recent years over allegations that he was her IRA commander during the early 1970s.
Mr Adams has denied being a member of the IRA or having any involvement in the kidnap and killing of Mrs McConville in 1972.
Researchers at Boston College last year lost a Supreme Court challenge in the US when they tried to block the release of the tapes after the PSNI launched a high-profile legal challenge to obtain the testimony.