POINT ISABEL - The dismembered body of a woman discovered this morning on the muddy bayshore could be that of Laci Denise Peterson, the pregnant woman who vanished from her Modesto home on Christmas Eve, a police source told the Times.

A tip from a citizen led police to the petite female body about 11:45 a.m., the source said on condition of anonymity. The head and legs were missing and it was apparent that she had been pregnant, the source said.

The body was clothed in maternity wear, the official said.

Police have not made a positive identification, but are pursuing the Peterson angle, the source said.

"We don't know for sure," the source said.

On Sunday, a tip led Richmond police to the body of a baby that had washed ashore near the Richmond marina. The body was discovered about 4:45 p.m. near Seabreeze Drive, police said.

The woman's torso was found less than two miles away from where dog walkers came across the body of a baby with its umbilical cord still attached. The body, found in the grass near the water, was badly decomposed.

The coroner's office said the newborn was a full-term baby boy.

Peterson, 26, was last seen alive about 9:30 a.m. Dec. 24 when her husband Scott Peterson left to go fishing in the Bay Area. He told police he tried to call his wife when he was done, but could not reach her.

He called police after returning home to find only the family dog with its leash still attached. Searches of a park near their home turned up no clues after Scott Peterson told police that was where his wife planned to take the family dog for a walk.

Police initially treated the disappearance as a missing persons case, but detectives reclassified the case as a homicide investigation in early March.

Investigators have repeatedly said they had no suspects, but Modesto police have searched Scott Peterson's home and vehicles and seized two family computers.

Suspicion among Modesto residents has focused on Scott Peterson, especially after he admitted having an affair with a Fresno massage therapist, Amber Frey. Laci Peterson's family disavowed support of her husband after the affair was revealed.

The investigation has ranged from the parks and canals of Modesto to the San Francisco Bay. Police searched the bay from the Berkeley Marina to Richmond and Angel Island, returning to Richmond last month to search the water with sonar and a remote-control underwater vehicle.

Last month, police searched the area where the baby's body washed ashore on Sunday. Authorities used sonar to comb the bottom of the bay, but failed to locate anything at that time.

Peterson said he had fished around nearby Brooks Island the day his wife disappeared, Modesto police have said. They searched the island, but found nothing relating to the investigation, they said.