An FBI dive team pulled up skeletal human remains from Lake Sonoma on Tuesday and Wednesday, sheriff's officials said Wednesday.

The effort to retrieve the remains began on Dec. 9 after a recreational diver reported seeing what appeared to be bones in about 100 feet of water, according to Lt. Carlos Basurto.

The Marin County Sheriff's Office dive team originally came in to help retrieve the remains, all bones, but was not able to recover most of them because of the depth and poor visibility, said Basurto.

An FBI dive team was brought in but was not available until this week, Basurto said.

"They were able to get the majority of the bones," he said.

The person's identity is unknown and there were no immediate signs of foul play, Basurto said. The Sonoma County Coroner's Office is now investigating the case.

Anyone with information is asked to contact the Coroner's Office at 565-5070.