Missing Glee star Naya Rivera is now presumed dead, police said.The actress went missing on Wednesday while on a rented boat with her four-year-old son at Lake Piru, about 56 miles north-west of central Los Angeles.The Ventura County Sheriff’s office said the effort to find the actress, best known for playing Santana Lopez on musical comedy series Glee, is now a "search and recovery operation".There is no foul play suspected and officers believe Rivera, 33, drowned.Police said a huge search