Footprints and historic campsite found in search for missing trampers Jessica O'Connor and Dion Reynolds

Jessica O'Connor and Dion Reynolds are missing in the Kahurangi National Park (background image). Photos / Greg Bowker, Supplied

Police have found footprints and a historic campsite near a river in the search for missing trampers Jessica O'Connor and Dion Reynolds.

The pair have not been seen since May 9 when they set off in the Kahurangi National Park.

Police said today they had not yet been able to confirm if either the footprints or the campsite near the Webb River belonged to the pair.

Today's land search was supported by a drone with infrared capabilities.

Police will begin using an Air Force NH90 helicopter and crew tonight.

A crew of four and a medic will be on board and will search inland from the Anatori River mouth.

It will search along river beds and will use night vision goggles to look for light sources, such as fires or torches, which might be being used by the trampers.

Police are asking for anyone who has been around the Anatori, Webb, Kokopu, Independent and Fraser rivers since May 8 who may have seen the pair to get in touch.

Anyone with information should contact police on 105 and quote event number P042228949.