Coroners have identified the victims as Robert Gordon, 68, and his wife Sharon, 57.

Police, who were called to the house in Orange at 5pm yesterday, have recovered a weapon, and say the investigation is continuing. The cause of the deaths has not been determined but according to the Orange County Register, police do not believe there are any suspects.

Robert Gordon, known as Baja Bob, was a successful off-road racer, and it was a branch of the sport that started his son's career, and to which he returned full-time after racing in Indy cars and NASCAR.

While he scored two Indy car wins in 1995 driving for Walker Racing, almost won the Indy 500 in 1999, and chalked up three NASCAR Sprint Cup wins between 2001 and ’03, Robby Gordon has found his greatest success in off-road racing, winning SCORE championships, Baja (1000 and 500) victories and stage wins on the Dakar Rally.

His Stadium Super Trucks series has also become hugely popular with fans, often providing support races for the Verizon IndyCar Series.

Gordon’s sister, Beccy, is the wife of 2012 IndyCar champion and 2014 Indy 500 winner Ryan Hunter-Reay. The pair's third son was born on Wednesday.

Anyone with information on the deaths of Bob and Sharon Gordon is urged to contact the Orange Police Department on +1 714 744 7444.