By Nicola Everett and Ellis Stephenson

More than 60 years have been added to sentences passed down to criminals who have been tried in Kent courts since 2012.

Figures from the Attorney General's Office show people who have been convicted of the most serious offences have had time added to their sentences after judges at the Court of Appeal found they were unduly lenient.

The case where the most time was added to a person's sentence was in 2015, where a drugs smuggling sentence was increased from eight years to 16. The case was heard at Canterbury Crown Court.

Last year 837 cases were referred to the Attorney General's Office, that is up by 124 from 713 in 2015.

The cases are brought to the attention of the attorney general after the case is reported by a member of the public or the CPS within 28 days of the sentence being handed down.

A team of solicitors and lawyers will then prepare a case file to be handed to the attorney general, who will then make a decision about case.

Within the file is information about the case, the reason it has been sent for review and court documents which include the judge's sentencing remarks.

The figures uncovered by research from KentOnline and kmfm show seven cases were challenged at Canterbury Crown Court and eight were reviewed from cases tried at Maidstone Crown Court.

Solicitor general Robert Buckland QC said: "We're finding now more and more people are returning cases they are concerned about to us through the scheme.

"We're happy to consider cases that are brought to our attention provided they're sent to us in the 28 days after sentencing, we can't consider cases after that time.

"Any member of the public is free to contact the Attorney General's Office and let us know about a particular case that concerns them.

"If we think there's been a mistake we will refer it to the Court of Appeal for its judges to decide whether there should be more time added to the sentence.

"I've been looking at the Kent cases I think Kent has had a large number of drug cases mainly because of the Port of Dover. These cases are brought because they are way too low.

"It's clear to me not only have you had a number of drug cases but serious assault cases.

"Now and again things do go wrong and the attorney and I have the safety valve of making these referrals so any mistakes can be put right and the Court of Appeal can help guide the judiciary along the right path.

"Mistakes are made and some cases are complicated and difficult. In the vast majority of cases judges are getting it right. Things do go wrong though when the judge goes below the guidelines and doesn't address why in court.

"What I do think, having been a part time recorder myself, is knowing there's a safety valve there is actually a source of strength for the judiciary.

"The need to maintain public confidence in the system of sentencing is part of what the attorney and I do when we look at these cases. I think our judiciary are the envy of the world but having said that there is accountability."

At the moment only the most serious offences are considered for appeal by the Attorney General's Office including serious sexual offences, crimes where violence is involved and high level fraud and drug importation and supply.

"Knowing there's a safety valve there is actually a source of strength for the judiciary" - Solicitor general Robert Buckland

The solicitor general also said the appeals scheme is due to be expanded to include terrorism offences in the future.

Each year the judiciary hands down around 77,000 sentences across the country and last year 150 of those were sent from the Attorney General's Office to the Court of Appeal with the belief they were too lenient.

In 2014 the sentence of Gravesend bouncer Alex Jetha was sent to the Attorney General's Office after he was sentenced to five years and eight months at Maidstone Crown Court for GBH with intent.

The sentence was increased to 10 years.

In another case in 2014 a sentence was passed down of 10 years, which meant the defendant would spend five years in prison.

The sentence was increased to seven years for public protection, meaning the defendant would serve two thirds of the sentence and then be eligible for release once the Home Secretary was satisfied they were safe to be back into society.