An Ipswich man who was the second in command of a criminal gang responsible for importing 4.5 tonnes of drugs, some of which came in through Felixstowe, has been jailed.

Leon Phillips, 46, exploited his freight industry contacts to transport the drugs around the UK. He was sentenced yesterday to three years and four months in prison for his role in the conspiracy along with Peter Brown, 42, from Sutton in Surrey, who was sentenced to four years.

Sentencing Brown and Phillips at the Old Bailey, Judge Lord Pontius said “this has been a huge investigation involving months of painstaking police work”.

Some 13 members of the group have now been sentenced to a total of 66 and a half years.

Over a two-year period, National Crime Agency officers followed the activities of Joseph Ashman, a prolific smuggler and the gang’s leader, as he attempted to distribute cannabis resin with a likely potential street value of £23 million.

Ashman, 46, from Rainham in Essex, pleaded guilty in 2014 to conspiracy to supply controlled drugs and money laundering and was sentenced to eight years and eight months in prison. His associate Kevin Hanley, another notorious drug trafficker, was jailed for more than 17 years in 2014 following a separate NCA investigation.

NCA investigators watched as Ashman met his associates at various locations to co-ordinate the delivery and distribution of the drugs using Phillips’ freight industry contacts.

When they saw Danny Malone, 45, from Tonbridge, Kent exchanging drugs, they alerted Kent Police and Staffordshire Police who arrested Malone and Robert Myler, 52, from Liverpool, seizing over 200 kilos of cannabis resin.

Malone was responsible for storing the drugs in Ashford, Kent, where 1.7 tonnes of cannabis resin was found.

Other members of the gang arrested in March 2013 include: Michael Malone, 49, from Hove, East Sussex, Martin Merritt, 41, from Manor Park, London and Hugh Webb, 54, from Dagenham.

Nearly 850 kilos of cannabis resin and 30 kilos of amphetamine were intercepted in May 2013. . James Bailey, aged 39, from Dagenham, Essex, Andrew Fraser, aged 51, from Ilford, Essex and Clive Brown, aged 61, from Dartford, Kent were arrested.

Undeterred, Ashman continued his activities, still monitored by the NCA. Working with the Eastern Region Special Operations Unit, officers executed a search warrant in June 2013 and recovered 1.8 tonnes of cannabis resin from an industrial site in Needham Market.

One of Ashman’s trusted confidants and customers was David Bland. In October 2013, Bland provided a courier, George Bell, aged 61, from Hull to collect 24 kilos of cannabis resin on his behalf. The NCA notified Northamptonshire Police who stopped Bell on the M1 motorway and arrested him. Bland was arrested by Humberside Police in January 2014, following surveillance activity and he pleaded guilty last week to conspiracy to supply controlled drugs.

The NCA’s relentless disruption of Ashman’s activities gradually weakened his financial status and he was forced to import smaller consignments of drugs.

In December 2013, officers worked with Suffolk Constabulary to seize a final importation of 30 kilos of herbal cannabis and arrested Peter Brown. Having taken out every one of Ashman’s team, NCA officers then arrested Ashman and Phillips in early 2014.

Brendan Foreman, Regional Head of Investigations at the National Crime Agency said: “Joseph Ashman was responsible for trafficking millions of pounds worth of drugs in to the UK using his trusted contacts to arrange their distribution.

“Investigations like this rely on commitment and partnership. The continued targeting of Ashman’s activities, by officers from the NCA and our colleagues in six separate police forces, eventually paid dividends. The evidence gathered against the thirteen group members was overwhelming and they all pleaded guilty to their crimes. The collaboration between UK law enforcement agencies has resulted in Ashman’s criminal empire being completely dismantled.”

Detective Inspector Eamonn Bridger from Suffolk Constabulary said: “We’re really pleased that justice has been done and that our hard work has helped put this prolific drug smuggler and his associates away for a long time. It’s a fantastic result, one that all of our officers involved in the case should be proud of, and a great example of the importance of joint agency cross-border working.”