Johnny Lewis died on 26 September
The actor’s death certificate states that his ashes were scattered off the coast of San Diego days after his body was found outside the home he was renting a room in, according to E! News.
Johnny, 28, is thought to have died after falling from the roof of the building in California.
Investigators have indicated that he’s suspected of killing his 81-year-old landlady and her cat, who were both found dead inside the property.
Johnny dated Katy, 27, in 2006 – before she met ex-husband Russell Brand – and they were photographed at a number of showbiz events together.
He played Marissa Cooper‘s friend Dennis ‘Chili’ Childress in The OC and had more recently appeared in shows Sons Of Anarchy and Bones.