Police said Luper was attacked by a group of masked intruders as he walked his dog near a neighbour’s driveway at about 23:30.
He was then dragged back to his home where the thieves used duct tape to tie up his wife and daughter and their au pair in an upstairs room.
The thieves took cash and jewellery worth about £100,000, including a rare Cartier watch, and escaped from the Lupers’ home.
Luper was later found by his wife and daughter in a downstairs room after they managed to free themselves.
Police were called but despite attempts to resuscitate him he was pronounced dead at the scene. Post-mortem tests showed he died from asphyxiation.