Jay Slater's desperate dad has said he 'can't understand' why his son would have decided to leave the road and descend into the rugged valleys surrounding the village he was last seen in.

The devastated family said they have now searched around '80 per cent' of the Valley of Barranco de Juan Lopez, close to the village of Masca, where Jay’s phone last pinged. But after moving on, Warren Slater said the road led to a sheer drop down a cliff edge - and he can't comprehend why Jay would have followed it down.

He also questioned why no-one had seen his son walking along the twisting road in a popular tourist spot, saying 'dozens' of cars would have passed him.

READ MORE: The nine theories devastating missing Jay Slater's family in Tenerife as conspiracy dismissed

“It doesn’t make sense, he’s either hid himself, but why would he hide himself? Or he’s just ….?," Mr Slater said. “We’ve done the valley where his ping was, we’ve gone up the road to a vantage point, there’s cliffs there and there’s a valley and a village there.” He said he couldn’t understand why anyone wouldn't choose to take the rough path and avoid the brambles and cacti.

“All I’m thinking is common sense, would you try and walk through there," he continued. "Where we’ve been today you can see there’s a hikers path with proper stones. We’ve gone straight down and you end up in the village.

“I’d go into the first building you see. An ideal spot for shelter is that little cave isn’t it, get a bit of shade, you’re hungover, get your head down in there. The police are convinced that’s where his last ping were”

Speaking of the thoroughfare on the road, he said: “From the bnb, he’s a fit lad, 25 minutes you can get to the top, to where the cafe is. If he’s followed the road and been where we’ve been today, it’s took him an hour and a half.

Jay Slater's brother Zak and dad Warren

“Dozens of cars would have gone past him. We got here at 9am and the 10am bus passed us. And it would have passed him. I’ve been up here three weeks and I’ve never seen as many cars."

Mr Slater has also called for more help from British authorities after Spanish police ended their search last Sunday. He said Jay is a 'British citizen' and he wanted to get 'Interpol involved'.

The family and some volunteers remain in Tenerife to search for Jay. On Monday, Mr Slater and Jay's brother Zak were pictured in Santiago del Teide, suggesting they are widening their search.