A UK boss of the Kinahan organised crime group who orchestrated a plot to amass an arms cache to dupe authorities in a bid to secure himself a lighter prison sentence has been jailed for six years.

Irish national Thomas Kavanagh, 57, had hoped that by leading the National Crime Agency (NCA) to a buried stash of 11 “fearsome” weapons, he could influence sentencing in a multimillion-pound drug smuggling case.

Running the conspiracy from prison, Kavanagh enlisted the help of his brother-in-law, 44-year-old Liam Byrne, and associate Shaun Kent, 38, in the plan to deceive the NCA.

Thomas Kavanagh admitted his part in the conspiracy last month (NCA/PA)

Byrne was jailed for five years while Kent was handed a six-year prison sentence after a two-day sentencing at the Old Bailey, with all three defendants appearing via video link from HMP Belmarsh on Tuesday.

The trio admitted the conspiracy last month ahead of their trial at the same court and Judge Philip Katz KC said during sentencing: “I propose to deal with this case as one overarching criminal plan.

“It was all designed to help Thomas Kavanagh with his sentence.

“The means chosen to achieve the purpose was to put together a cache of firearms to fool the NCA… and in due course to fool the judge.”

The judge called the weapons “fearsome”.

In May 2021, Kavanagh provided information to the NCA which led them to a field in Newry, Northern Ireland, where two holdalls were unearthed.

They contained seven machine guns, three automatic hand guns, an assault rifle and ammunition.

The plot was foiled after the NCA uncovered incriminating messages on encrypted EncroChat which had been cracked by French counterparts.

Firearms from the illicit stash of weapons which were seized by the NCA as part of a ruse by Irish national Thomas Kavanagh (NCA/PA)

Kent was said to have performed several roles, including “messenger boy” by receiving instructions from Kavanagh via a middleman in prison.

He then used his EncroChat device to relay instructions to others tasked with him to obtain the guns and ammunition, the court was told.

Byrne was a close criminal associate of Kavanagh as well as his brother-in-law and they lived near to each other in Tamworth, Staffordshire.

He acted on Kavanagh’s direction to acquire firearms and ammunition and added “much-needed impetus” to progressing the plot.

Kavanagh, Byrne, from Dublin, and Kent, from Liverpool, admitted last month ahead of their trial at the same court two charges of conspiring to possess a prohibited weapon, and two charges of conspiring to possess prohibited ammunition, between January 9 2020 and June 3 2021.

Kavanagh and Kent also admitted conspiring with others to pervert the course of justice.