Sean Callaghan, 64, of Rayleigh, worked at two law firms in Essex, BMTK Solicitors and then briefly at Palmers, before his new employer discovered his fraudulent activity, which had gone undetected over an 18-year period from 2003.

Callaghan had worked at BMTK for more than two decades and was a partner at the firm for 15 years until he left for the new job in 2019.

During the course of his time at BMTK he repeatedly edited payment details to divert funds from client accounts to accounts he controlled, inflated client fees for his own personal gain, and falsified invoices.

In one case in 2008, while handling the case of a deceased woman’s estate, Callaghan altered the amounts the beneficiaries were supposed to receive and concealed more than £20,000 of her estate before paying the money into his own business account just days after paying her surviving family.

Callaghan used the money to fund his lavish style with home renovations, and purchases of a classic car and a property abroad at the expense of the clients and firms he represented.

In 2019 Callaghan joined a different law firm, Palmers, and continued his offending, but the new employers discovered false invoices and reported the incident to Essex Police.

An investigation was opened by the police, while BMTK Solicitors and Palmers Law also launched their own probes and began civil recovery proceedings.

Detectives at Essex Police discovered that more than a dozen individuals and businesses were either defrauded or used by Callaghan to move and conceal payments made into his accounts, and the total loss to the clients and firms affected totalled £396,228.77 over the 18 years these offences were detected.

At Southwark Crown Court on 5 July, he pleaded guilty to 17 charges of fraud and two charges of theft, and at the same court he was sentenced to four years in prison earlier this month.

Speaking after the sentencing, detective Thomas Blackmore of Essex Police, said: ‘Callaghan was in a position of trust over his clients, yet he operated a complex web of deception to exploit their funds.

‘He did this over and over, with total disregard for those he was stealing from, in one case even a family’s inheritance.

‘Callaghan utilised multiple business accounts for the fraud and on some occasions had client funds sent directly to contractors he was employing for the maintenance and renovation of his properties.

‘The sums in this case are shocking, but much worse is the long-term impact on the people and businesses whose money he has taken.

‘It was only right he was given a custodial sentence and hopefully it emphasises that those who abuse their position will be punished.’

A spokesperson for BMTK said: ‘BTMK is pleased that the Solicitors’ Disciplinary Tribunal (SDT) struck off Sean Callaghan as a solicitor, following Callaghan’s admission of professional misconduct, including misappropriating funds belonging to BTMK and its clients, and providing false information to both.

‘Callaghan was involved with BTMK, and its predecessor firm, from 1996 until April 2019. When we were made aware of concerns, we took immediate action and we have set aside funds which we have identified should be reimbursed to affected clients and we are working at pace to locate those clients and complete their full reimbursement. These clients comprise only a very small number of the firm’s clients overall, and a very small proportion of the firm’s business.’

Callaghan only been with the second law firm Palmers briefly when the fraud was discovered.

A spokesperson for Palmers said: ‘Prior to working for us at Palmers, Sean Callaghan had been a partner for over 15 years at another local practice. He had been a Deputy District Judge over the same time frame. He came to us cloaked in the reputation of being a trusted advisor to his loyal client base and in the spotlight of what was, on the face of it, a lengthy and distinguished career.

‘Having received no indication from anyone that he had a history of financial and other irregularities affecting his clients and others, he joined us in mid-2019 and we uncovered his attempted and fraudulent activities in very short order.

‘Notwithstanding the level of sophistication, investment of time and effort and the planning involved in his offending, our robust systems and our excellent team enabled us to identify that something was not right, following which we immediately and thoroughly investigated.

‘Our investigators quickly concluded that Mr Callaghan had been diverting funds to his own bank accounts and discovered that he had been doing the same thing whilst at BTMK.

‘We dismissed Mr Callaghan, alerted BTMK, reported the matter to the police and other authorities, and immediately notified each of the clients whom he had brought with him from BTMK, who had continued to be the focus of his fraudulent behaviour.

‘It is good to know that the process has reached a conclusion and the fact that he has now received a custodial sentence for his repeated thefts, frauds and abuse of position is of some comfort. We are grateful to our diligent, honest and proactive staff who were instrumental in the discovery of wrong-doing and which ultimately led to this result.’