Police are continuing to search a river for a missing 16-year-old who was last seen heading towards the water while naked and "tripping".
Nathan Wood, from the Paignton area, was seen by the River Dart at Swallowfields, Totnes, in Devon, at about 6pm on Friday.
Friends have told police he consumed a new psychoactive substance (NPS) before taking his clothes off near the river.
A canoeist contacted police at about 7pm on Friday after spotting Nathan "tripping" as he headed towards the water.
There have been no sightings of Nathan since then and it is not known whether he entered the river, though friends reported hearing a splash.
Inspector Tracy Sharam said dive teams would continue to search the River Dart on Sunday.
"We believe he has entered the water because we have done two days of land searches," she said.
She said there had been sightings of Nathan naked near the water but none since he was seen by the canoeist.
Police divers, the police helicopter, police dogs and search teams took part in the operation to look for Nathan on Friday and Saturday.
The search for the teenager - described as being 5ft 6in, of slim build with gingery fair hair - resumed on Sunday morning.
Speaking on Saturday, Inspector Sharam said: "A member of the public called police reporting that he had seen a teenage boy naked and in a distressed state, running towards the river.
"He was seen running through a field near the school and although no-one actually saw him enter the water, his friends heard a splash.
"Officers have been searching the area, including the river. However, he has not yet been found.
"He may have been under the influence of a potential new psychoactive substance and we are becoming increasingly concerned for his welfare."
Nathan's bag, shoes, wallet, trousers and hat have been recovered by police.
Anyone with information is asked to call police on 999 quoting reference 775 of August 5.