A solicitor who "callously betrayed" two vulnerable clients when he stole more than £700,000 from their medical negligence damage awards has been jailed for four years.

Personal injuries lawyer Marcus Nickson, 66, from Wigton, Cumbria, wrongly overcharged the families of the brain-damaged claimants in legal costs to enrich himself and his law firm, Preston Crown Court heard.

He helped secure £3.5 million for the family of a baby girl born with catastrophic brain injuries in 1999 which left her permanently disabled, and who later died in 2012.

He also successfully contested a claim on behalf of a 22-year-old man who suffered a stroke in 1996 which left him permanently disabled and went on to receive £3 million in damages from the negligent health trust.

But Nickson went on to steal sums of £104,000 and £606,000 from the two clients as he billed them for unwarranted fees which he transferred into his company's office account.

His offending came to light in 2013 after the Carlisle-based KJ Commons & Co Ltd ran into financial difficulties following the death of senior partner Kevin Commons - one of taxi driver Derrick Bird's victims in his shooting spree in west Cumbria in June 2010.

Another medical negligence lawyer examined the files of Nickson, also a partner at the firm, and passed on concerns over his billing methods to the police who began an investigation.

Last month, Nickson, of Blencogo, pleaded guilty to two counts of theft.

On Monday, his barrister, David Whittaker, told the court that the reputation of the "highly regarded and respected" solicitor of 40 years was "in tatters".

Although it was no excuse for his dishonesty, he said Nickson had been suffering from depression during the time of the offences and had previously spoken of heavy work pressures and of being bullied by Mr Commons.

He had recently been diagnosed as having bipolar disorder, Mr Whittaker said.

Mr Whittaker said Nickson did not personally benefit from the monies taken but had profited as a partner in the law firm.

He submitted there was "almost no attempt" at deception in that he told both families what he was doing in charging them but just did not tell them why.

Rejecting that argument, Judge Simon Newell told the defendant: "They (the families) had to come to terms with rebuilding their lives, doing their best for their damaged children, providing for those children and engaging with you in complex legal procedures that would have been totally above their head.

"To suggest there was not an element of sophistication and/or planning in this does not seem to me to be realistic. These were complex, difficult and esoteric matters."

He said Nickson had acted in a "thoroughly professional way" in securing substantial damages for the families which they "deserved, needed and wanted as a result of medical negligence".

But the judge said in stealing part of those damages he could not think of a higher degree of trust being breached than that of a legal adviser to the parents of two brain damaged young people.

Following sentencing, Cumbria Police financial investigator Barry Cowin said: "Nickson is a cruel individual and his actions are nothing short of despicable. He had the full trust of both victims after initially working to win their awarded claims, he then callously betrayed them. I am pleased that he has been brought to justice for his crimes.

"I hope that today's sentencing can provide some form of closure to the victims in this case and their families. They have been extremely brave throughout our investigation."