With its panoramic views over the Mediterranean, and absolute privacy, the ground floor spa facilities of the luxury cliff-top villa, in a quaint Spanish coastal village, must have been a draw for countless wealthy tourists looking for a summer holiday.

Who wouldn’t be seduced by photos of the relaxing ‘oasis’ on the property’s website – the in-shot bottle of champagne and two glasses next to the hot tub suggesting the manner in which prospective holiday makers might want to kick back and relax with loved ones.

So it must have been for Patrick Tobin and his wife Thomasina when they booked the sprawling three-storey Villa Luna, in Cullera, south of Valencia, for a two-week break with their two teenage children this summer.

They should have been packing up now, preparing to head back to their home in Greenwich, south-east London, and the daily grind of juggling family life and successful careers.

Instead, this family has been destroyed and plunged into a macabre story of almost unimaginable horror.

Patrick and Thomasina are both dead, and the children – a 16-year-old daughter and 14-year-old son, both of whom have special needs – are now coming to terms with the tragic loss of their parents in a mystery that is deepening by the day.

The only firm fact in this troubling tale is that Patrick and Thomasina’s bodies were found naked beside the hot tub in the spa area in the early hours of August 25. Initial tests suggest both died after suffering from cardiopulmonary arrest, but the cause remains unknown.

In the past ten days, multiple theories have been bandied around. Had the couple been electrocuted or died from chemical poisoning? Had they overheated or overdosed, after some evidence of drug use was allegedly found at the scene? Foul play was quickly ruled out by investigators.

The latest update from the police suggested the couple had been trapped in the tub after it malfunctioned, causing a powerful suction. Superficial injuries allegedly found on their bodies seemed to suggest some sort of struggle or rescue attempt.

But who was trying to rescue who, and from what, remains subject to wildly conflicting speculation.

The last theory, however, is one several people with knowledge of how hot tubs function have been quick to dismiss.

Francisco Quero, a spa technician in the Valencia area, told the Daily Mail he did not believe the model they were in would have been capable of malfunctioning in such a way.

He said: ‘This is a privately owned [hot tub] on private property, which means its motor runs on two or three horsepower maximum [equivalent to a large lawnmower or pressure washer].

‘It is very strange that an adult would get stuck in the suction system. A baby might get stuck but not an adult.

‘Even if the grill, which usually protects the suction system was taken away, an adult might get stuck for a moment, they might have a bit of a scare and be left with some bruises, but that’s all.

‘There could have been an electric shock, causing a person to lose consciousness and block the suction, but... it does not make sense to me.

‘It is impossible to get stuck in one of these devices and not be able to get out. I am not an investigator, and I have not seen the equipment but I would rule out that hypothesis.’

This disbelief was echoed by the CEO of Goccia Spa – the company where a tub for Villa Luna was bought and installed in 2019.

Defending his company, Carlos Navarro said he had not been informed that one of his company’s hot tubs was involved in the accident and claimed the spa bath shown in videos of the villa from 2021 was not the one sold to the owners seven years ago.

Mr Navarro additionally told the Daily Mail: ‘I have visited factories all around the world and seen many different designs and it is practically impossible for something like this to happen at hot tubs installed in the home.

‘The suction is caused from two holes at the bottom and both have security nets. Maybe these nets broke and the owner never replaced them.

‘It is very improbable but there may have been a chance that one of the holes became covered by something and blocked, causing all the suction to go through the other hole. But I still don’t think this would be enough pressure for an adult to get stuck. There are security measures that cause [hot tubs] to switch off every 15 minutes as well.’

He added that warranties on his spa tubs only last for two years and liability would lie with the owners if safety nets were not changed. So what did happen?

Today at Villa Luna, located in the exclusive hillside gated community Cap Blanc, little outside evidence of the tragedy remains. The police cordon previously in place has now been removed and blinds and shutters have been pulled down across the home’s huge windows.

The managers of Colina Del Sol, where Villa Luna sits alongside two other properties behind electric gates, refuse to speak of the case. They continue to live on site and tend to the properties. Neighbours claim to know nothing.

Even the Guardia Civil refuse to give further insight while they wait for the results of tests, such as the toxicology report. The date this is expected remains unknown.

A spokesman told the Daily Mail: ‘As there is an ongoing investigation, we are not making any comment.’

What is certain is that the horror that has unfolded would have been unimaginable two weeks ago when Mr and Mrs Tobin – by all accounts a popular, hard-working and well-respected couple – boarded a flight from London to Spain with their children.

The family of four, who lived in a modern, four-bedroom semi-detached home a stone’s throw away from Greenwich Park, had intended to spend a fortnight at the secluded cliff-top villa, which costs around £2,600 a week.

With its own private pool, the indoor spa and outdoor BBQ area, the 2,691 sq ft home, is owned by brothers and business moguls Adam and Michal Markuszewski, who bought the plot in 2018, before building Colina Del Sol, consisting of three villas, and opening it in 2020. Mrs Tobin, 51, who was originally from Co Monaghan in Ireland, had lived in the UK for the last three decades, most recently working as a quantity surveyor for high-end hotels at the consultancy firm Turner and Townsend.

Mr Tobin, originally from Wellington in New Zealand, also had a successful career, working as a general manager in the London branch of HCLTech, an Indian company that specialises in digital engineering, cloud and AI products.

Devastated colleagues paid tribute to them both this week while neighbours said the family had lived happily in their home for the past eight years.

A mother and son, who did not want to be named, said: ‘They were a lovely couple. It’s so tragically sad what happened. They were very kind.’

The details of that fateful day, on August 24 – just two days after their arrival – are sketchy. There had been a BBQ lunch, police sources told local media, followed by a dip in the pool.

By late afternoon, the teenagers had retreated to their rooms and their parents headed down to the bottom floor to enjoy the spa facilities, described as being made for ‘moments of pure relaxation’.

Yet somehow this quiet downtime quickly turned into a disaster, with officers still, ten days on, trying to piece together what happened. Foul play was quickly ruled out after inspections and CCTV showed no signs of forced entry into the property, however, investigations will also test for any drug use.

As previously mentioned, officers have speculated that the pair were victims of so-called ‘suction entrapment’, which is caused when a strong vacuum created by the hot tub’s hydro-massage feature drags a person’s hair, clothing or body into a vent.

Sources close to the investigation suggested that one of the couple had got into trouble in the water, the other spouse then lost their life in a desperate rescue effort.

Conflicting claims have been made about who tried to save who from the water, however, preliminary autopsy results reported by local newspaper Levante-EMV claim Mr Tobin had more pronounced deep, bruises in the shape of the suction of the vent.

The exact timing of the pair’s death is also unknown but at around 7pm, their son went to look for his parents to find them both lying naked not in – the hot tub. The boy, believing the pair were taking a nap, left his parents in the spa.

Given the children’s special needs, perhaps this wasn’t a wholly unusual reaction.

The teenager then went to rejoin his sister, where they prepared dinner before going to bed.

The grim reality was only revealed the next morning when the boy went to wake his parents at 5am, for a planned sunrise trip to the beach, and found their bed untouched from the previous day.

He then walked downstairs to discover his parents still lying cold in the same position they had been in the previous evening.

At this point, the traumatised boy alerted his sister. Panicking, the siblings then contacted a relative over the phone who told them to alert a neighbour.

After walking around the streets of the gated community, the children eventually found a woman who, despite the language barrier, realised the gravity of the situation and called 112 – the country’s emergency line.

Shortly after, an ambulance, along with the local police and Guardia Civil, rushed to the property, but Mr and Mrs Tobin were pronounced dead at the scene by paramedics.

As for the children, understandably in shock and saying very little, they were cared for initially by the Spanish Red Cross and Cullera City Council, who brought in two psychologists for guidance and looked after them until extended family members arrived.

They are now with relatives staying at unknown accommodation in Valencia until Mr and Mrs Tobin’s bodies are repatriated back to Ireland for their funeral, which will take place in Mrs Tobin’s hometown of Cabra, Castleblayney.

Their remains are being held at the Institute of Legal Medicine of Valencia, until the final autopsy report is completed.

Mrs Tobin leaves behind her 87-year-old father Tommy McArdle, who was director of Irish broadcaster RTE and goalkeeper for the Monaghan Football Team in the 50s and 60s, as well as eight siblings.

Mr Tobin is survived by both his Wellington-based parents, Clare and Michael Tobin, as well as his three sisters.

While their relatives were this week too devastated to speak, the family’s announcement of their death said: ‘Thomasina and Paddy shared a life filled with love, family and friendship. Their sudden passing has left an immeasurable void in the lives of all who knew and loved them.’

A case is now being prepared for Judge Nadia Maria Oviedo Malo at the civil investigations unit in the nearby town of Sueca, where it will be determined if any parties are liable for negligence.

When approached by the Daily Mail this week, the owners of the resort offered their ‘deepest condolences’ to the family and added the resort had operated for many years without any incident and ‘has always maintained the highest standards of safety and quality’.

In the meantime, a devastated family attempts to comfort two teenagers as they try to make sense of the horror that has enveloped their lives.