Ventura County Sheriff’s Department Capt. Eric Buschow said during a press conference: “This may well be a case of drowning.”

Former Glee actor, Naya Rivera, is missing after her 4-year-old son was found alone on a boat in Lake Piru on Wednesday, July 8.

The search for the 33-year-old actor began after she and her son, Josey, failed to return a rented pontoon boat following an afternoon on the Californian lake.

According to the authorities, another boater discovered Rivera’s boat drifting on the lake approximately three hours after they left the dock. Josey was found alone, asleep, and wearing a life jacket.

An adult-sized life jacket, presumed to have been Rivera’s, was discovered on the boat. Her identification was also onboard and her car was found nearby.

Joey, who authorities confirmed was “in good health”, is reported to have told investigators that his mother was swimming but “did not come back up” to the boat.

Ventura County Sheriff’s Department Captain, Eric Buschow, said during a press conference that there was “no evidence of foul play” but added, “this may well be a case of drowning”.

He said: “They were seen going out on the lake together in the early afternoon, and approximately three hours after they left the dock another boater out on the lake discovered the boat drifting with the [son] on board asleep.”

He went on: “We’re going on the belief that she did go in the water, and we’ve not been able to locate her. This may well be a case of drowning.”

Buschow confirmed that authorities had been “actively searching” with both aerial and dive teams since the alarm was raised, and further resources would be deployed on Thursday morning.

Divers and helicopters were seen scouring the lake until evening, but no trace of Rivera was found, and the search was suspended “until first light” on Thursday.

Buschow said search and rescue teams from neighboring counties would join on Thursday, to provide more divers and air units.

“This is a big reservoir. It’s deep. These kinds of things happen,” he added. “We don’t know all the circumstances. Investigators are working on that, getting as much information as possible.”

Rivera is best known for playing the role of Santana Lopez in Glee. Within hours of the news breaking, her former costars began sending messages of prayer and hope on social media.