Jay Slater's best friends fly back to the UK as desperate search for missing teenager continues in Tenerife

Missing Jay Slater's best friends have returned to the UK three weeks after the apprentice bricklayer's mystery disappearance, MailOnline can reveal.

Lucy Mae Law and Brad Hargreaves flew out to the Spanish holiday island with Jay for an eight-day holiday last month, taking in the 72-hour New Rave Generation festival.

The three friends - all 19 - and another teenager, Brandon Hodgson were all last together at Papagayo nightclub in the raucous resort of Playa de las Americas on June 17. 

Brad had stayed on in Tenerife with his mum Rachel - although he was not seen taking part in any searches - and was spotted at Tenerife south airport late on Sunday night.

Brad is believed to have returned to his home at Oswaldtwistle, Lancashire, with Jay's uncle Glen Duncan, 41, who on Saturday was seen searching a valley where the missing raver's mobile last pinged.

It is understood Lucy headed home some time earlier after doing all she could to help in the now four week search. 

It is the latest development in the search for the missing teenager which has seen:

• MailOnline reveal the shady criminal underworld of Tenerife, which is rife with ruthless British drug dealers battling Italian mafia for control;
• Jay's father Warren call for Interpol to get involved after claiming Spanish police's probe into his son's disappearance 'stinks';
• The reason why the missing raver refused a lift from a 'new pal' as he tried to walk home from a remote £40-a-night Airbnb on foot be revealed;
• The identity of 'Johnny Vegas' be revealed as the convicted drug dealer who was one of the last people to see Jay before he disappeared;
• Best friend Lucy Law break her silence on Instagram to share a new picture of missing Jay.

Among those searching for Jay was his mother Debbie, 55, father Warren, 58, and brother Zak, 24, Rachel, 34.

They were joined by a group of expats and local hikers who combed through the valley all day after police called the search off on June 30.

When asked how long the family would stay Glen said he had to 'get back as his children were at school' and added of Warren and Debbie:  I don't know how long we're going to be out here for. How long's a piece of string?

'Debbie and Warren won't be going anywhere.'

Brad was seen in the queue to board a Manchester bound flight from Tenerife and had earlier been seen browsing the cigarette section of the duty free shop.

Brad, who has also been on holiday with Jay spoke about the last time he heard from his pal on the phone.

Describing the last moments he saw him, Brad gave an interview to this morning on June 28 saying that while he was on the phone to Jay, he could hear his 'feet sliding down the hill'.

He said: 'Yeah that's how I knew he went off the road. You could hear like when you walk on gravel, stones.'

Brad admitted, however, he wasn't worried at that point as Jay reassured him he was fine - but he did tell his friend to put his location on.

Brad added: 'We were both, like, laughing about it. He said: 'look where I am'.'

He said Jay then cut off as he had another call waiting - but promised to phone back. 

Both Brad and his mum Rachel vowed to stay in Tenerife for 'as long as it takes' to support Jay's distraught family but he is believed to have returned home due to his work commitments.

It is understood Lucy headed home some time earlier after doing all she could to help in the now four week search.

Taking to her Instagram for the first time since Jay vanished, Lucy posted a snap of the pair together with a crying face emoji last week.

Lucy was also the one who set up a GoFundMe to raise money for Jay and to help fund the search. It has since reached over £50,000.