The father of missing Jay Slater says the investigation is “stinky” and asks why two men who drove him to a remote AirBnB were excluded from any involvement

• Warren Slater criticised the Spanish police’s response to his son’s disappearance

The father of missing Jay Slater has questioned why two men who drove his son to a remote AirBnB in Tenerife could not have had anything to do with his disappearance nearly three weeks ago.

Warren Slater, 58, spoke after completing a grueling eight-hour search in 25-degree heat under a scorching sun in a remote valley where Jay’s phone last beeped on June 17.

Just hours earlier, 19-year-old Jay had been driven to the mountain village of Masca by a convicted drug dealer (identified by MailOnline as Ayub Qassim, 31) and another man who could not be identified; despite being among the last to see him, both were deemed “irrelevant” by Spanish police.

“Everything stinks. It’s just a mystery and I don’t know the outcome,” Warren said.

Ayub Qassim had previously stated that he had invited Jay back to his rented holiday home after a rave party in the hours before his disappearance on June 17. He had previously told MailOnline: “He came to my Airbnb alive and he left my Airbnb alive.”

Warren told MailOnline: “We are going around in circles. You can’t shout at the Spanish police because they do nothing.”

“If you start screaming and shouting, they will definitely not do anything. If they want to search a house, they have to go to court first.”

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“You need Columbo,” he added. “So when you get home, get me a Columbo.”

Warren, who was assisted in the search by his other son Zak, 24, is in Tenerife with Jay’s mother Debbie Duncan, 55.

Everyone has vowed to stay there until the missing bricklayer’s apprentice from Oswaldtwistle, Lancashire, is found.

He said: “This is the fourth time I’ve done this. It was hard, I almost poked my eye out. Tell me where to look, I can only go by the last sighting, the woman in the restaurant saw him going the wrong way.”

“What kind of person lets a little boy go astray?”

Warren also criticized participation in the “last action” last Saturday, when only six people responded to a call by Spanish police for volunteers to search the remote Parque Rural de Teno.

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He said: “I was quite disappointed when they started searching last Saturday. They said the whole island would be uncovered.”

“Let the big boys do it,” the police told me, “the big, big search took place on Saturday. We arrived in the valley at 2 p.m. and there wasn’t a soul there.”

“Maybe they were there, I don’t know, maybe they were there before me. But I was pretty disappointed because I expected every fire truck, every ambulance, every onlooker and every prostitute to be looking for him.

“The way they presented it when they said they were going to conduct the biggest search ever.”

To vent his frustration, he said: “You walked from that B&B at 9am, you walked all the way here – he’s a young, fit guy – all the way.”

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“You mean to tell me there is no car and no one saw him at half past ten? Why are you going down there? You have to stop. Why go any further?”

“Why are you leaving this street? You have no idea where you are. And no one else has seen him. He knocked on a woman’s door at 10 o’clock and he went in the wrong direction.

“This morning I saw her, she wouldn’t stop. It’s somebody’s son, you know when you’re the last person to see somebody’s son you try your best to help, don’t you? She must be a grandmother.

“What would you do if your son were here? If he were on top of the rock, you would climb him.”