The son of the UK boss of the Kinahan organised crime gang will walk free from prison after admitting his part in an arms cache plot to get his “notorious” father out of jail early.

Jack Kavanagh, from Tamworth, was a trainee accountant when he tried to help his father, Thomas “Bomber” Kavanagh, 57, engineer a lighter sentence for drug smuggling.

The plot involved acquiring and then hiding a stash of handguns, machine guns and ammunition and then alerting the National Crime Agency (NCA) to its location with X marking the spot on a map.

Although I accept you got involved out of misguided loyalty to your father, you entered into this agreement with your eyes open

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

Jack Kavanagh was arrested in May 2023 at Malaga Airport by officers from the Spanish National Police while he was travelling from Dubai to Turkey.

He was extradited to the UK where he pleaded guilty to conspiring to possess firearms and ammunition.

On Thursday, Judge Philip Katz KC accepted Jack Kavanagh was more of an “enthusiastic messenger” than an “organiser” as he sentenced him to three years and one month in prison.

Because he has already effectively served his time on remand, the sentence means the defendant will be released from Belmarsh prison, from where he appeared by videolink for his sentencing.

Judge Katz told him: “Although I accept you got involved out of misguided loyalty to your father, you entered into this agreement with your eyes open.”

Unlike, Thomas Kavanagh, who was “a notorious and leading member of an organised crime group”, the defendant had no previous convictions and was a young man of good character, the court was told.

The judge noted Jack Kavanagh had been 20 when he got involved in his father’s scheme and had “promising career” as an accountant.

In earlier mitigation, the defendant’s barrister Tyrone Smith KC said: “This was a young man with a real opportunity in life to make good on his promise and was seeking to do so.

“He was not motivated by financial gain or the result of a longstanding criminal life but of misplaced loyalty.”

Mr Smith said the encrypted chat revealed that other plotters had a knowledge of criminality that Jack Kavanagh “simply did not”.

Serving inmate Peter Keating, 43, from the Republic of Ireland, was jailed for four years and eight months on Thursday, having admitted the same charges, as well as one of plotting to pervert the course of justice.

He is expected to be returned to Ireland where he is already serving 12 years for directing a criminal organisation.

His barrister, Tim Moloney KC, said Keating was acting under direction, was put under pressure to comply and had since “severed” all contact with his co-defendants.

Opening the facts of the case, prosecutor Max Baines said the conspirators had agreed to acquire as many firearms as possible from the UK, Netherlands, the Republic of Ireland and Northern Ireland between January 2020 and June 2021.

At the time, Thomas Kavanagh was in HMP Dovegate where he was serving a three-year sentence for possession of a stun gun and had been on remand for serious drug charges since March 2020.

Those charges related to smuggling “multiple kilos” of cocaine and cannabis into the UK, for which he was jailed for 21 years in 2022.

Thomas Kavanagh had also enlisted the help of his brother-in-law, 44-year-old Liam Byrne, of Dublin, and associate Shaun Kent, 39, of Liverpool.

In May 2021, Thomas Kavanagh provided information to the NCA which led them to a field in Newry, Northern Ireland, where two holdalls were unearthed that contained seven machine guns, three automatic handguns, an assault rifle and ammunition.

Both Keating and Jack Kavanagh featured in encrypted chats about the plot.

Jack Kavanagh, who used the handle BasilBadger, communicated with Bryne and Kent about obtaining guns and was referred to by them as Junior.

In September, Thomas Kavanagh, Byrne, and Kent admitted their roles in the conspiracy.

Irish national Thomas Kavanagh was jailed for six years which he will serve consecutively with his earlier jail sentences.

Byrne – who fled to Majorca after the events – was jailed for five years while Kent was given a six-year prison sentence.

Craig Turner, deputy director of investigations at the National Crime Agency, said: “Kavanagh and Keating were a central part of this plot to deceive us in a bid to reduce the lengthy sentence Kavanagh’s father was facing for drugs offences.

“Their messages showed they were involved in much of the logistics of the plan to obtain the firearms, all of which were viable deadly weapons.

“While Jack attempted to evade justice by fleeing abroad, our global reach and close working with international partners saw him returned to the UK and now starting a lengthy prison sentence.”