Spanish police wearing forensic gear have searched the holiday cottage where Jay Slater stayed the night before he disappeared.
The missing British teenager visited the farmhouse in northern Tenerife with two men after attending a music festival in Playa de las Americas.
He was last seen walking away from the cottage on June 17 and later called a friend to say he was lost and desperately thirsty.
It comes despite the Guardia Civil calling off the search for the apprentice bricklayer from Lancashire over the weekend, after 13 days of searching.
However, two officers in plain clothes, wearing forensic-style blue slip-ons over their shoes, were seen searching the cottage where he stayed, which is known as Casa Abuela Tina, on Tuesday morning. The property in the mountain village of Masca is listed for £40 ($83.50) per night on Airbnb.
As one of the officers left the property, he told MailOnline: “I’m afraid I can’t tell you anything about the investigation or our search inside.
“If you want any details, speak to headquarters, I’m not allowed to talk to you. My colleague and I are from the judicial police and carrying out our own work.”
Slater’s mother and father, Debbie Duncan and Warren Slater, later visited a Guardia Civil station in Playa de las Americas for two hours on Tuesday.
As the pair left the station, Duncan, 55, told reporters: “It’s a mystery and he’s still missing, we need to just let these guys get on with it”.
She added: “Keep it going, keep it alive. Let them (the police) get on with it, we’ve got to trust in these people”.
Slater, 58, said they would return to the police station “when they ask us to”.
The Telegraph understands that Slater’s family, including his older brother Zak, 24, will stay in Tenerife to continue the search for him.
Duncan later issued a comment through the British overseas missing persons charity LBT Global, saying that “words cannot describe the pain and agony we are experiencing”.
She said: “Jay is a normal guy who is in his 3rd year of an apprenticeship, and he is a very popular young man with a large circle of friends.
“We are a very close family and are absolutely devastated about his disappearance. Words cannot describe the pain and agony we are experiencing.
“He is our beautiful boy with his whole life ahead of him and we just want to find him. We do not have any information on his whereabouts.”
She added: “The Guardia Civil have worked tirelessly up in the mountains where Jay’s last phone call was traced.
“We are aware of the conspiracy theories and speculation on social media and some websites, and can only describe this as vile, the negative comments are extremely distressing to our family.
“We also embrace the love and support we have received from across the globe. It has not gone unnoticed, especially his home town in Oswaldtwistle, Lancashire.
“As a family we would like the world to respect our privacy at this present time.”
Speaking after the search was called off on Sunday, Rachel Hargreaves, a close family friend who has joined them on the island, told The Telegraph: “Nothing has changed. We will continue to search for him”.
Slater had travelled to Tenerife with two friends including Hargreaves’ son, Brad. He went missing on June 17 after he left a music festival in a car with two British men he met that night.
They travelled to the holiday rental cottage in Masca, and Slater was last seen walking up a steep road in the early hours of June 17.
After setting off, he rang a friend and said he was lost, thirsty, had one per cent charge left on his phone and had cut his leg on a cactus. His phone ran out of power shortly after the call and was last traced to the Rural de Teno National Park.
The Guardia Civil has insisted the two men last seen with Mr Slater “don’t have any relevance” to the case. The men, who are believed to be from South East England, have returned to the United Kingdom.
Cipriano Martin, head of the force’s Greim mountain rescue unit, said: “We’re mountain specialists and we’re in charge of searching here, and it’s the Civil Guard investigators who have been responsible for the investigation.
“Those men have been spoken to and they don’t have any relevance whatsoever for the case.”
The force is also refusing to treat Slater’s disappearance as a crime at this stage. It has told a female investigating judge that they see nothing yet that points to Slater being the victim of a crime.
Despite calling off its search, the Guardia Civil said the case remains open and that a “parallel” investigation is ongoing.