A TEENAGER has been found covered in leeches after being lost in dense bushland for nine weeks.Matthew Allen, 18, was last seen leaving his Westleigh home on the morning of November 27 last year.
Despite weeks of extensive searches in surrounding bushland, police were unable to find him, eventually fearing the worst.
But about 2pm on Saturday, two experienced hikers spotted the 18-year-old lying in dense bushland, Detective Acting Inspector Glyn Baker from The Hills Local Area Command said.
He was just 1km to 2km from home.
Detective Baker said Mr Allen was covered in leeches and bites, was disorientated and suffering from dehydration and exhaustion.
He is believed to have lost up to half of his bodyweight.
"The missing person stated that he had been living in the bush for nine weeks and drinking water from an almost dry creek bed," Detective Baker told AAP.
While Mr Allen's injuries aren't considered life-threatening, police said he was likely suffering from a "rather severe" case of gangrene on his feet and lower legs.
"He was not living under shelter and was exposed to full conditions," Detective Baker said.
Detective Senior Constable Ben Wrigley from Hornsby Local Area Command, who was involved in the case from the start, says police are "amazed" the teenager is alive.
"Anyone who is missing for that length of time in those kind of conditions - you wouldn't expect to see them again," he told AAP.
Detective Wrigley said he's grateful he can finally provide the Allen family with some answers.
"I was amazed and very happy that everything turned out they way that it happened," he said.
"I couldn't believe it."
Mr Allen, who has an underlying medical condition, is recovering in Hornsby Hospital.
When he went missing, police said they held serious concerns for his welfare after finding he had not taken his mobile phone with him, and had not accessed his bank accounts or made any contact with his family.