Several members of Naya Rivera's family have joined in the search efforts for the missing Glee actress. Rivera was presumed dead Thursday, after going missing the day before.

Naya RiveraGregg DeGuire / Getty Images

"Naya's mother and brother have been at the lake every day since Naya disappeared. They have been in constant contact with the Sheriff's Office and involved in the search. On Saturday morning, they joined the search on a sheriff's boat," a source tells PEOPLE.

Pictures showing Rivera's father swimming in the water where she was lost surfaced online in the days after her disappearance. Her ex, Ryan Dorsey, also joined in the search.

"Unfortunately, they did not locate Naya Rivera. They are still searching," Ventura County Sheriff's Office Captain Eric Buschow told reporters at a Friday press conference. "We don’t know if she’s going to be found five minutes from now or five days from now."

Rivera's 4-year-old son Josey was found alone on a boat on Lake Piru, earlier this week. She had taken her son swimming and disappeared. Josey told authorities that his mother never returned to the boat while they were swimming.

"I think at some point in time we will find her," Ventura County Sheriff Sgt. Kevin Donoghue told PEOPLE. "I will say that we are hopeful to find her. We want to bring peace and closure to the Rivera family. This is a tragic event."