The Ombudsman, Winnie Chiu, has launched an investigation into how the Planning Department and Lands Department police unauthorised land use in the New Territories.

Initial inquiries have shown that the Planning Department receives some 1,500 complaints every year about unauthorised development, many of which are upheld, Chiu said on Thursday.

She added that many of these are repeat complaints and some involve conservation areas.

The Planning Department is responsible for tackling unauthorised work such as pond filling and land excavation, as well as change of land use, while the Lands Department deals with the illegal occupation of government land.

The Ombudsman will look into how the two departments carry out their responsibilities and work together on complaints.

Chiu said land is a valuable social resource, and failing to act on unauthorised development is bad for society and, potentially, the ecosystem.