Multiple search and rescue agencies are scouring bushland south-west of Sydney as they hunt for a man last seen nearly two weeks ago.

Darren Banks, 57, was last spotted at a home in Macquarie Fields, about 4pm on March 15.

Police found his vehicle on the Starlights Trail at Wattle Ridge on Thursday, about 15 kilometres west of Bargo in the Macarthur region.

Investigators believe Banks might have been bushwalking towards Ahearn lookout or Emmetts Flat campground area, about an hour south of Campbelltown.

There are serious concerns for his welfare as it is considered out of character for him not to be in contact with his family.

Detective Inspector Andrew Mackay said Banks had previously bushwalked in the area, known for its difficult terrain, and there was no evidence he had been unwell before going missing.

“He packed his belongings, got in his car and left, there was no concern and he was due to return to see his family on the weekend,” he said.

“It is quite remote out there deep in the bush and there is not a lot of people out there.”

Banks was not carrying a mobile phone, although he did have a GPS device. He was also carrying only limited supplies.

“Darren loves bushwalking, he’s camping most of his time,” Mackay said.

“[But] it’s been almost two weeks since anyone’s had any contact with him.”

Experts from police search and rescue and the NSW State Emergency Service have been called in to join the efforts.

“There’s been a combination of aviation support over a number of days and night and on foot, but there is no vehicular access,” Mackay said.

Banks is described as being of Caucasian appearance, of medium build, about 180 centimetres tall, with short brown hair, a beard and brown eyes.

Anyone who has been in the Starlights Trail area and has seen Banks, his vehicle or has information on his whereabouts is urged to contact Crime Stoppers.

-with AAP