The Mountain Safety Council believes a tramper's decision to head off alone was a leading factor in his death.

This comes in Coroner David Crerar's findings into the death of 42-year-old Brock Oliver, who died while tramping at Mt Aspiring National Park at the beginning of the year.

On the fifth day of the tramp Mr Oliver became tired and decided to leave the group he was with, following the river back to the hut.

Police believe he became stuck in rapids and was washed away.

His body was found more than two weeks later.

A Mountain Safety Council report found his decision to travel by himself back to the hut was a contributing factor, and that if he had stayed with the group, his death would have been avoided.