In an unexpected twist, a hand-drawn ‘treasure map’ scrawled on a notepad within the confines of a high-security prison became the key to uncovering a hidden cache of firearms. This map, a critical piece of evidence, guided law enforcement to a secluded field where 11 guns lay concealed beneath the earth.

The origins of this intriguing discovery trace back to Thomas ‘Bomber’ Kavanagh, the notorious head of the Kinahan cartel’s UK operations. In an effort to secure a reduced sentence for his involvement in a £30 million drug smuggling operation, Kavanagh handed over the map to the police.

However, his plan backfired when the National Crime Agency (NCA) uncovered evidence that Kavanagh himself had orchestrated the purchase and burial of these weapons. This revelation thwarted his hopes for leniency and further implicated him in criminal activities.

Offering an exclusive perspective on this unfolding drama, the Daily Mail shared insights from the lead detective on the case. Known only as ‘Matthew’ for his safety, the officer recounted his initial encounter with the conspiracy and reflected on the broader implications of Kavanagh’s capture on the global operations of the Kinahan cartel.

While detained and awaiting sentencing on drug-related charges, Kavanagh produced the map that ultimately led authorities to two buried holdalls. These contained a significant arsenal: seven machine guns, three automatic handguns, and an assault rifle, underscoring the magnitude of the threat posed by the cartel’s reach.

From his cell where he was awaiting sentence on drugs charges, Kavanagh produced a map which led police to unearth two buried holdalls containing seven machine guns, three automatic handguns and an assault rifle.

But his plan was foiled after messages on EncroChat – an encrypted platform described as ‘WhatsApp for criminals’ – were cracked by French law enforcement and passed on to the NCA.

These revealed Kavanagh had sought the help of associates, including his 24-year-old son Jack and brother–in law, Liam Byrne, to amass as many weapons as possible before trying to trick the NCA by ‘revealing’ the cache.

Kavanagh, who was already serving a 24–year sentence for drug smuggling and an unrelated firearms charge, was handed another six–year prison sentence for the conspiracy, bringing the total to 30 years. 

This handwritten map was passed to police by Thomas ‘Bomber’ Kavanagh – UK chief of the notorious Kinahan cartel – in a bid to get a lighter sentence over a £30m drug smuggling plot

It was accompanied by a list of bullet points showing police how to find the buried weapons 

A court recently heard Thomas Kavanagh made more than £12m from importing drugs. The criminal – who is now behind bars – was recently ordered to repay £1m of this total

Recalling his reaction when he first realised what Kavanagh had tried to pull off, Matthew told the Mail: ‘It’s not the first time someone facing a lengthy prison sentence has tried to use this kind of tactic – these people will go to almost any lengths to avoid prison time.

‘But it was quite shocking in the sense of the position he held and the type of people he was associated with.

‘Kavanagh was the highly trusted and highly organised lieutenant of the Kinahan organisation in the UK. That’s a massive drugs market with big purchasing power.

‘To take out that top ranking lieutenant would have been a huge blow to the Kinahan organisation crime group.’

The kingpin’s downfall is covered by a new podcast, Underworld: Behind the Scenes of the NCA, which sees Matthew and several senior colleagues provide a rare insight into their remarkable investigation.

David – another NCA officer who also uses a pseudonym – remembers being immediately suspicious when Kavanagh’s legal team handed over the map with an ‘x’ over a field near a country lane in Newry, Northern Ireland.

At the time, in May 2021, Kavanagh was in HMP Dovegate serving a three–year sentence for possession of a stun gun, and on remand for drugs smuggling charges, following his arrest in 2019. 

Police excavated the field to find a stash of weapons, including machine guns, handguns, and an assault rifle

Just some of the 11 firearms and ammunition that police recovered 

David told the Underworld podcast: ‘The map itself was just on clear notepaper, almost a classic ”x marks the spot” treasure map, with a number of lines indicating roads, the perimeter of the field, a gateway and then an X on the map.

‘Given the location of it in Northern Ireland, there was potential for any stash of weapons to be booby trapped – so the risk was very high.’

After a period of reconnaissance to look out for any suspicious activity, the site was excavated by specialist teams, who found two buried holdalls containing seven machine guns, three automatic handguns and an assault rifle.

Unfortunately for Kavanagh, his revelation coincided with a French law enforcement operation that had gained access to EncroChat, where messages showed he had had been discussing the movement of firearms with a series of associates.

A new police probe, Operation Briered, went on to identify them as Kavanagh’s family members Jack Kavanagh and Liam Byrne, and two other associates, Liverpool criminal Shaun Kent and Dubliner Peter Keating.

Officers linked the men to their anonymous EncroChat handles using a variety of evidence. This included personal photos they had shared on the app, as well as locations that could be cross-referenced with CCTV. 

The messages also revealed splits within the group, with Keating calling the gun plot ‘mad’ and claiming Bomber was pushing his trainee accountant son Jack, who he described as ‘a soft kid’, into crime.

Kavanagh lived in a highly fortified house in Tamworth, Staffordshire, which had bullet proof windows 

At the house, police found a fearsome stash of weapons, including machetes, axes and baseball bats

Thomas Kavanagh, Keating and Kent were already in custody and admitted to their roles in the conspiracy last September. Keating, 43, was jailed for four years and eight months, while Kent, 38, received a six-year sentence.

Jack Kavanagh and Liam Byrne had already fled the country but were tracked down and jailed for three years and one month and five years consecutively.

NCA officer Matthew described the takedown as a significant blow to the Kinahan cartel.

He told the Mail: Not only was Kavanagh gone. Liam Byrne, who was thought to be taking his place, was caught too. So, it was a double blow.

‘That said, there’s always someone willing to step into the vacuum.’

Kavanagh lived in a highly fortified house in Tamworth, Staffordshire, where police found a fearsome stash of weapons, including machetes, axes and baseball bats.

Asked by the Mail why Kavanagh felt the need to have so many weapons, Matthew linked them to the Kinahans’ ongoing feud with fellow Dublin outfit the Hutch gang, which has already claimed 18 lives.

Liam Byrne, Kavanagh’s brother-in-law, and Liverpool criminal Shaun Kent 

The plot also involved Jack Kavanagh, Bomber’s trainee accountant son 

‘Someone at that level will be thinking he needs access to some form of self-defence – the more deadly the better,’ he said.

‘You’re not talking about giving someone a slap and teaching them a lesson – they’re actively seeking to kill each other.’

Matthew said the NCA was continuing its work to target other senior Kinahan members, including the group’s leader, Daniel Kinahan, who is believed to be based in Dubai with his brother, Christopher Kinahan Junior, and father, Christy Snr.

Investigations are also underway against other senior gang bosses.

‘For every Thomas Kavanagh that the public are aware of there are probably another 20 of them of the same calibre that are not known to the media that we are working on,’ he said.

‘Even if someone thinks they’re not being investigated, they probably are. This investigation took the best part of five years.’

• The second series of the National Crime Agency podcast, ‘Underworld: Behind the Scenes of the NCA’, will be available from Wednesday 12 November across all listening platforms, including Apple Music and Spotify.