The search for missing teenager Jay Slater has sparked a "parallel investigation" by Spanish Police, as the hunt for the 19-year-old reaches its tenth day.

The Lancashire teen went missing more than a week ago on the island of Tenerife, after telling a friend he was going to walk back to their accommodation as he had missed the bus.

Rescuers have now brought in specialist search dogs from Madrid, as they continue to comb the rugged mountain terrain where he was last seen for clues.

Speaking to GB News, journalist Gerard Couzens claimed that the team investigating the case has "no plans to end the search" and does not intend to "scale down" their operations.

However, Couzens revealed that the case has since sparked a "parallel investigation", as they have failed to find any trace of Slater after ten days.

Couzens explained: "The search operation is continuing on the ground and in the air. There is a parallel investigation ongoing, but the police are not discussing that aspect of things.

"But we know through a local mayor on the island that they have been looking at CCTV footage and speaking to witnesses who say they saw someone who could be Jay in different parts of the island."

When asked by host Andrew Pierce if the Spanish Police are considering "calling off the search" after ten days without any progress, Couzens affirmed that they are "not considering" calling it a day on the case yet.

Couzens told GB News: "There will obviously come a time when an end is brought to this search, but publicly, the police are not talking about an end date.

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"Sniffer dogs from Madrid have been brought in, so publicly at least, police are not saying that they are even considering bringing an end to this search or scaling it down.

"But obviously the family are aware that there is a good chance that if Jay is found, he's sadly not going to be found alive."

When pressed by Andrew on how someone such as Slater can "just disappear" without a trace, Couzens revealed the police's theory is that Slater "most likely became disorientated and got lost".

He added: "It is a very, very difficult terrain. The police's lead theory is that he simply became disorientated and got lost, but they are not ruling anything out.

"They are looking at other possibilities - he could be with people, for instance. They have said from day one they are investigating a series of leads, and they are not ruling anything out."

Offering optimism for the Spanish Police and for the search for the missing 19-year-old, Couzens assured that the "publicity" of the search for Slater means they "still believe" he is out there somewhere.

Couzens concluded: "The very visible search and the fact that they brought reinforcements in yesterday, tends to suggest that they believe that he is lost out somewhere out there.

"God forbid he's gone into the sea, they haven't done sea searches yet. But they are, as we know, looking at other possibilities."