Natalie Wood Investigation Robert Wagner NOT a Suspect

11/18/2011 10:30 AM PST

Natalie Wood Death Investigation -- Robert Wagner NOT a Suspect

Robert Wagner is not a suspect in Natalie Wood's death -- this according to the L.A. County Sheriff's Department -- but a spokesperson says they've received new information that was "substantial enough" to reopen the investigation.

Lt. John Corina wouldn't go into detail about the new information during a news conference -- but said it was credible, and that two homicide investigators have been assigned to the case ... 30 years after Natalie's drowning was ruled accidental.

Lt. Corina also wouldn't say if Natalie's body would be exhumed, or if Christopher Walken -- who was on the boat the night of Natalie's death -- would be interviewed.