Officers, who were called to the property in the Croft Park area at around midday, said their inquiries are at an early stage.
Police had said they were keen to trace the man’s blue Toyota Rav, which had a registration number M301 ORO, as it had not been in its usual spot outside Mr Gardner’s home when he was found dead.
However, officers have confirmed the vehicle has now been traced in Perth and thanked members of the public for their help.
It has not yet been divulged exactly where the car was discovered, and the investigation into Mr Gardner’s “suspicious” death will continue into the weekend.
Anyone with information is being asked to contact Police Scotland on 101 or Crimestoppers on 0800 555 111.
For the latest, see Saturday’s Courier.
UPDATE: Balbeggie death: Police find dead man’s car