New Zealand pilot Phillip Mehrtens has been freed more than 19 months after being kidnapped by armed separatists in Indonesia's Papua, authorities said on Saturday.

Mehrtens was freed and picked up by a joint team in the Nduga area and was undergoing health check-ups and a psychological examination in Timika regency, the Indonesian police said in a statement.

Indonesia's Metro TV showed him tearfully speaking to his family by phone.

A faction of the West Papua National Liberation Army (TPNPB), led by Egianus Kogoya, kidnapped Mehrtens on February 7, 2023, after he landed a small commercial plane in the remote, mountainous area of Nduga.

"Through the long process of negotiation, with patience not to do it repressively, our priority has been the safety of the pilot through this long process," Indonesian President Joko Widodo said in televised remarks.

New Zealand Foreign Minister Winston Peters said, "We are pleased and relieved to confirm that Phillip Mehrtens is safe and well and has been able to talk with his family. This news must be an enormous relief for his friends and loved ones."

A range of New Zealand government agencies had been working with Indonesian authorities and others towards securing Mehrtens' release, Peters said in a statement.

Indonesian Brigadier General Faizal Ramadhani, head of Cartenz 2024 Peace Operations, said, "We are prioritising approach through religious leaders, church leaders, traditional leaders and Egianus Kogoya's close family to minimise casualties and maintain the safety of the pilot."

Another New Zealand pilot, Glen Malcolm Conning, was killed by separatist rebels in Papua in August after landing his helicopter in a remote area, authorities said at the time. (Reuters)