Her 4-year-old son was found alone on a rented boat.

Police in Southern California fear the actress Naya Rivera she had gone swimming with her son, who got back into the vessel, but she did not.

Rivera (33) is best known for playing Santana on the TV series Glee and has gone missing on Lake Piru.

Her four-year-old son was reportedly found alone on a rented boat.

The child was wearing a life jacket but it is thought Rivera was not as a life jacket was found on the boat, according to NBC Los Angeles.

Officers say a search will start again at first light.