LYNN – Police divers aboard the Salem harbormaster’s boat probed the murky waters of Sluice Pond and the Saugus River Tuesday, following up the latest lead in the missing persons case of Alice Nunes of Peabody.The 58-year-old woman was last heard from on Dec. 15 telling her daughter by cell phone that she was driving her 2003 black Lexus ES350 with Massachusetts license plate 21GX72 and about to hit some water at approximately 8:45 p.m.An extensive search was conducted but Nunes was never found. Police later determined that the cell phone signal had bounced off a tower near Wyoma Square, leading investigators to assume she vanished within a 15-mile radius.Area residents watched as the police divers entered and exited the water Tuesday near the Lynn bank of the Saugus River but there was no sign that Nunes’ car had been found.The Item was told a sophisticated side-scanning sonar device aboard the Salem boat had picked up the image of what appeared to be a submerged car in the river, but divers found only a sunken vessel.Nunes is described as 5-foot-4, with light brown hair and brown eyes.Detectives from Lynn and Peabody have been investigating the disappearance.