BLUE MOUNTAINS, Sydney, NSW, Australia - A search in the Blue Mountains for a man that was launched on Sunday night was called off late Monday morning when the body of a man, believed to be that of the missing person, was discovered.

Blue Mountains police were alerted late Sunday afternoon that the man, from the Sydney suburb of St Ives, had gone missing while canyoning with a group of friends in the Wollangambe River, Mount Wilson.

The man, aged 39, became separated from the group around 3pm Sunday and two hours later, Blue Mountains Police initiated the search, which continued through until nightfall, with the support of PolAir and NSW Ambulance personnel.

A command post was established at Mt Wilson Rural Fire Service and the search resumed on Monday morning at 9am, restricted by heavy fog, which delayed the start of the search. The fog also prevented the use of helicopters.

The body of a man, believed to be that of the missing canyoner, was found about two hours later, around 11:00am.

A report will now be prepared for the Coroner.

(File photo).