Disabled pensioner left battered in Melbourne home invasion

Victorian police are hunting a man who savagely bound, gagged and punched an intellectually disabled pensioner during a violent home invasion in Melbourne's north.

Seventy-year-old Rob was at home in his assisted-living unit in Preston at 3am on Sunday when the offender jumped the back fence and forced him back into his bedroom.

The intruder bound Rob's wrists and ankles and tied him to the bed. Blindfolded and gagged, he was repeatedly punched to the head.

The man used Rob's own suitcase to steal his father's war medals, two mobile phones, cash and disability cards.

Rob was found lying on the floor by his carer at around 9am.

Rob's sister Gail Burge said it is the stolen war medals he cares about the most.

"It makes you so angry that somebody could do that to someone who is so fragile," Ms Burge said.

"It's bad enough coming and stealing his money, and then walking out the door. But to do this, is just terrible."

Neighbours heard nothing, but said they have also been woken by strangers knocking at the door.

"It was 2.45am in the morning and some strange person came to my door, and asked if Allan lives here," neighbour Andrew Dacy said.

Rob is still in shock from Sunday morning's ordeal and is now too scared to return home to his unit.

He is being looked after in a hotel room, but his sister said she will soon need to find more suitable accommodation for him.

Police have urged for anyone who knows what happened to come forward and "explain their side of the story".

The offender is described as Caucasian in appearance, with a tall, thin build.

He was wearing dark coloured clothing at the time of the attack, with a black leather hat discovered in the back yard.

Anyone with information is urged to contact Crime Stoppers on 1800 333 000.