NSW search resumes for swimmer

A file photo of a rescue helicopter
A search has resumed for a 19-year-old man who vanished while swimming off the NSW north coast. -AAP Image

A search has resumed for a swimmer missing overnight at Lennox Head on the NSW north coast.

Police were called to Seven Mile Beach by a woman reporting she'd seen a swimmer in difficulties in the surf about 6pm on Friday.

Officers began a search immediately involving local lifesavers, the force's marine rescue command, ambulance personnel and the Westpac Rescue Helicopter.

Personal belongings were found unattended on the beach near the surf club before a man approached police with concerns his 19-year-old son had not returned from a swim, around 7pm.

The search continued until 10pm without success and resumed at 6.30am on Saturday.

Water police and Marine Rescue NSW are currently conducting sweeps off the coastline.