Australian soldier's body found on US mountain

An autopsy will be conducted on Australian soldier Captain Paul McKay after his body was found near the summit of New York's Scarface Mountain.

The discovery of his body on the mountain, a popular hiking site in upstate New York with an elevation of 932m, ends a two-week search for the 31-year-old from Canberra.

"This is not the outcome we had hoped for," Saranac Lake police chief Bruce Nason told AAP on Thursday.

There were grave concerns for Capt McKay, who was suffering post-traumatic stress disorder after a tour of Afghanistan and was on leave from the Australian Army.

Capt McKay sent an email to his father on December 30.

In the email Capt McKay said he was leaving all of his possessions to his father.

The last sighting was on New Year's Eve when a witness saw him walking along train tracks near Scarface Mountain.

The region was hit by extremely cold weather, caused by the polar vortex, which resulted in snow storms and temperatures falling below minus 30 degrees Celsius.

Chief Nason said the cause of death was yet to be determined and he was unaware if a note was found with Capt McKay's body.

The soldier was found in a section of the mountain that was hidden from helicopters searching for him.

A New York forest ranger who climbed the mountain found the body on Wednesday.

"The family has been informed of this news and we express our deepest sympathy for their loss," Chief Nason said.

* Readers seeking support and information about suicide prevention can contact the Suicide Crisis Helpline 0508 828 865 (0508 TAUTOKO).