The 59-year-old, who had gone out to search the area in East Ardsley after realising it was missing, was found by his 31-year-old son at about 10.30pm on Thursday night.
The pair had split up to canvas the area when they discovered the son's motorbike had been taken from the garden of the house in Cave Lane.
The younger man had performed CPR on his dad in an attempt to save his life, with medics giving emergency treatment after arriving in an air ambulance.
Police have confirmed today that a 21-year-old man, arrested in relation to theft, has now been released under investigation and enquiries are ongoing to identify further suspects.
The stolen bike, a bright yellow Honda with the registration V699 PCX, has not yet been found, they added.
Police had received a number of reports of it being ridden around the Middleton area of Leeds on Thursday night. CCTV from the Cave Lane property shows that the Honda was taken by four suspects who had arrived on two motorbikes.
Leeds District CID’s Det Insp Richard Holmes had stressed there was nothing to suggest any suspicious circumstances into the man's death, adding that officers were doing everything they could to support the family.
Anyone with information is asked to ring Leeds District CID on 101 or Crimestoppers anonymously on 0800 555111.