KNBC-TV, Los Angeles, reported on the request for the recordings of interviews between convicted killer Tex Watson and his attorney to determine whether the recordings contain information on homicides connected to the Manson family, the Los Angeles Times reported.
Police sources stressed it was just a preliminary inquiry and they didn't know if the recording would provide any new evidence, the report said.
Watson was denied parole for the 14th time last year.
Relatives of his victims requested parole be denied for his involvement in the killings of actress Sharon Tate, who was eight months pregnant, and four others at her Beverly Hills home on Aug. 9, 1969. The next night, Watson helped kill grocery owners Leno and Rosemary LaBianca.
Watson had been given the death penalty but it was later overturned.