A search is continuing in Southern California for former Glee star Naya Rivera, who went missing during a boating trip on Lake Piru on Wednesday.

The Ventura County Sheriff's Department earlier said the search would continue with dive teams at first light.

The search operation was launched on Wednesday after Rivera's four-year-old son was reportedly found alone on a rented boat at Lake Piru on Wednesday.

Lake Piru

Rivera, 33, is best known for playing high-school cheerleader Santana Lopez on musical comedy series Glee.

The search resumed at daybreak on Thursday, with helicopters, boats, divers and sonar teams expected to be involved.

Naya Rivera as Santana Lopez in Glee alongside Lea Michele as Rachel Berry

Rivera's son, Josey Hollis, is in good health and with family, police have said said. He told officers his mother put him back on the boat but never got back on herself.

On Tuesday, Rivera tweeted a picture of herself and her son together, which was captioned: "Just the two of us."

A number of celebrities have called for prayers for the missing actress, including singer Demi Lovato and Harry Shum Jr, who played Mike Chang in Glee.

Another of the show's stars, Heather Morris, wrote in her Instagram story: "We need all the prayers we can get to bring our Naya back home to us. We need your love and light."

Jackée Harry, who appeared in the sitcom The Royal Family, posted a clip of her acting alongside Rivera.

"Please God, don't cut this life short," she said.