Police are investigating a south-west Sydney man who allegedly shot a home intruder with a bow and arrow.

The 68-year-old man shot the intruder after confronting him at his home on Glanara Court at Wattle Grove yesterday afternoon, police said.

Officers said the unknown man broke into a couple's home on Glanara Street in Wattle Grove and stole a large amount of cash, a handbag and car keys.

The man then went to the garage of the home and entered the couple's vehicle, a Nissan X-Trail.

As he started the car and attempted to reverse out of the garage, the male resident — at home with his wife during the robbery — armed himself with a bow and arrow and went to the garage.

The resident confronted the robber with the bow and arrow, causing him to crash the vehicle into a fence, police said.

The intruder then got out of the car and jumped a fence into Wattle Grove Drive, running towards a parked Mazda Tribute.

As he ran away, the resident stood up on the fence and shot the fleeing man using the bow and arrow, hitting him in the bottom or lower back area, police said.

The intruder — who was wearing a black, short-sleeved shirt — escaped, driving off in the parked car.

Police were called and attended a short time later.

The intruder allegedly drove a stolen car into a fence when confronted by the homeowner. ( ABC News: Jessica Kidd )

Police warn public not to approach intruders

Detective Inspector Dean Johnstone said police were still hunting for the intruder and were also investigating the circumstances in which the arrow was fired.

"At this point in time we have been given information by the homeowner, police have attempted to speak to him," he said.

"He's maintained his right to silence, this is a matter we'll investigate."

A crime scene was established and examined by forensic specialists. The bow and arrow and other items were seized by police as exhibits.

The bow and arrow are not prohibited weapons, but Detective Inspector Johnstone suggested there was a possibility the man could face charges.

"The owner is part of an archery club and takes part in that sport," he said.

"This is very early days in the investigation but … we are investigating all facets of the incident."

Detective Inspector Johnstone advised people not to confront intruders, following the unusual incident.

"My advice to people would be to comply with [the intruder], not to confront them, certainly not to engage them in a physical altercation, let them go and let us investigate," he said.

Doctors asked to look out for unusual injuries

Police said inquiries with hospitals had yet to locate anyone treated for an injury consistent with this incident.

The man who broke into the home is described as being short and of Caucasian appearance with dark hair and olive skin. He has a tattoo on the left arm above the elbow.

He is believed to be between 30 to 35 years old.

Detective Inspector Johnstone said police were asking doctors and medical professionals to look out for anyone with unusual injuries.

"We believe the arrow may have struck the offender in the buttocks or the lower back region," he said.

"We'are asking anyone in the medical profession … to contact police if a person comes in with a wound [consistent] with an arrow striking them."