Constable Romana Biserko searched the Parmelia home last week, finding the original medals mounted in a frame alongside a photo of Richard Arthur McDonald.
The medals were taken to Fremantle police station, where officers used the service number on the plaque to search the National Archives and find the owner.
Police discovered Mr McDonald had passed away in 1984 but that he had a wife called Daphne who had an address in Queensland.
After subsequent calls to Queensland police, local officers discovered Daphne had also passed away, with no other relatives recorded.
They then phoned the Royal Australian Navy, who were able to track down Mr McDonald’s son Kim. The medals had been stolen when thieves burgled his Rockingham home in May. Last Friday, Constables Michelle Rich and Jodie Parker were able to return the medals and photographs to Mr McDonald.