Update: 3.01pm

NSW Police said authorities have located the crash site of a missing light aircraft in rugged terrain north-west of Casino.

The site was located by the Westpac Rescue Helicopter about 9.45am today, approximately 1.5km into the Koreelah National Park.

NSW Police, with the assistance of NSW Police Rescue and SES volunteers are currently attempting to access the site from the ground, this will take some time as the site is located in very steep and rugged terrain.

More information will be available in due course. The families of those on board are being kept appraised of the search efforts.

8.47am

A search is underway for an overdue plane which left Casino Airport, bound for Boonah, Queensland on Sunday afternoon.

The single-engine aircraft, with two people on board, left the airport about 2pm on January 12, and was due to arrive in Boonah about 3pm (NSW time).

When the plane failed to arrive as planned and the pilot was unable to be contacted, a search was co-ordinated by the Australian Maritime Safety Authority (AMSA).

The Westpac Rescue Helicopter was tasked to search an area of the Tooloom National Park, west of Woodendong, but nothing was sighted.

Search efforts will continue this morning under the direction of AMSA.  

Anyone with information about the missing plane to urged to contact Triple Zero (000).

Anyone with information about this incident is urged to contact Crime Stoppers: 1800 333 000 or https://nsw.crimestoppers.com.au

Information is treated in strict confidence.