Australian police have found human remains in their search for a Sydney grandfather who they believe was kidnapped by mistake almost two weeks ago.

Widower Chris Baghsarian, 85, was forcibly taken from his home in North Ryde just before dawn on 13 February, with CCTV showing a group of masked men bundling him into an SUV.

Police say the incident was most likely a case of mistaken identity, and local media have reported the intended target was a relative of a man with links to a well-known organised crime family.

On Tuesday, police confirmed they had found human remains near a golf course on the outskirts of Sydney, after an earlier search located a burnt out car.

Police had found a blood-stained carpet in the boot of the car, which was linked to the alleged kidnappers and an abandoned property where it is believed Baghsarian was held hostage.