Police in California suggest a man suspected of killing nine of his family members lived a life of polygamy and incest.

Police chief Jerry Dyer of Fresno says Marcus Wesson, 57, fathered two of his victims with his daughters.

He says Wesson was co-operating with the police.

Wesson emerged from his home Friday covered in blood after initially refusing to come out. Police had come to the house after getting calls from two women who said they wanted to reclaim their children from Wesson.

Authorities discovered nine bodies entangled together in a room. The scene was so disturbing, police officers required counselling after seeing the bodies.

Dyer says Wesson will be charged with nine counts of murder.

Investigators say the victims included six females and three males, ranging in age from one to 24. They say he had children with at least four women, including two of his daughters.

Dyer says neighbours have reported seeing many women wearing long dresses, and sometimes veils.

Frank Muna, who once sold his house to Wesson, said the 57-year-old's behaviour had become more bizarre in the past three years. Muna said Wesson was forced to leave the house after neighbours started to complain.

Wesson's 29-year-old son, Dorian, has told newspapers that his father wasn't abusive at all. He said he hasn't seen his father in a year.

"I want to give him the benefit of the doubt," said Dorian Wesson.

Fresno, a city of 440,000, is about 300 kilometres southeast of San Francisco.