Search on for missing NSW kayaker

A search for a missing kayaker is underway in NSW's Kosciuszko National Park.

The 49-year-old set off alone on from the Tom Groggin campsite between Khancoban and Thredbo on Sunday afternoon, heading down the Upper Murray River.

However, he never arrived at the next rest area, where he was expected a couple of hours later.

It is believed that he had a helmet, life jacket and water with him in the kayak.