The 32-year-old-man was at the house in Boronia Street, South Granville, with another man, aged 58, and a woman, aged 54,  when they heard a knock on the door about 10.15pm.

When the older man went to investigate, he was confronted by a man and woman armed with knives who pushed their way inside the house, police said.

The pair threatened the younger man and demanded money. His hands were cut during the attack.

After rummaging through the property, the intruders fled with cash and were last seen running east on Boronia Street.

Officers attached to Rosehill Local Area Command launched an investigation.

A crime scene was established at the house, which was examined by forensic specialists.

Despite an extensive search of the area with the help of the Dog Unit, the man and woman have not been found.

The younger man was treated at the scene by NSW Ambulance paramedics for minor injuries to his hand.

Police said they did not believe the incident was targeted.