A Canterbury district coroner has been hit with a formal warning for taking more than five years to complete an inquest into the death of a teenage boy.

North East Kent's Rebecca Cobb was reprimanded by the Judicial Complaints Investigations Office (JCIO) after a complaint from the family of 17-year-old Adam Scott.

The Barton Court pupil died after a crash in Chestfield in February 2007, but the inquest was only concluded in April 2012.

The delay sparked a complaint from Adam's mother, Deborah Scott, and led to the warning being issued to Ms Cobb, who is set to retire in June.

A JCIO spokesman said: "Coroner Rebecca Cobb has been issued with a formal warning following a complaint that she failed to deliver her verdict upon the inquest into the death of Adam Scott within an appropriate time frame.

"The Lord Chief Justice and Lord Chancellor are of the view that coroner Cobb's conduct fell short of that expected from a judicial office holder and have issued her with a formal warning."

Adam suffered broken legs when his car crashed after hitting ice. He was expected to make a full recovery, but died in Margate hospital three days later from complications that led to a fat embolism of the brain.

Mrs Scott, a teacher from Molehill Road, Chestfield, has told how the delayed inquest verdict added to her distress.

She said: "The whole inquest hearing process lasted more than five years and we were put through a huge amount of emotional stress.

"I wrote to the coroner many times about the delays and, although sometimes I got a prompt reply, on other occasions I got no acknowledgement and it took six to eight weeks. It all added to our distress.

"We also submitted a separate complaint to the hospital, which told us it needed a transcript of the inquest, which took the coroner 12 months to provide."

Among the other long-running uncompleted hearings is the inquest into the death of groundworker Callum Osborne, 24, from Canterbury, who died when a trench collapsed on him at a building site in Swalecliffe in April, 2011.

An inquest was part heard in December 2012, but adjourned and his mother Karen Hodgson recently lodged a formal complaint with the JCIO about the delay.

The family has now just been told it will be continued in March on a date yet to be fixed.

Under new rules and guidelines, recently announced by the Chief Coroner, inquests should - except in special circumstances - be completed within six months.

According to the latest statistics published on the Ministry of Justice website, there were 114 North East Kent hearings still open or in progress at the end of 2012 - half of which had taken more than six months.

Of the total, 26 had been open between six and 12 months, 12 between one and two years and 19 more than two years.

But the statistics also show that of those completed in 2012, the average time was 21 weeks. No figures are available for 2013.

Kent County Council is responsible for appointing new coroners and meeting all the costs of the service.

Spokesman Murray Evans confirmed a letter was received from Miss Cobb announcing her intention to retire in June.

He added: "Inquests can take longer to conclude because of delays in receiving reports from hospitals, crash investigation experts, pathology and post-mortem departments, and reports of investigations into deaths abroad, all of which impact on the ability to conclude an inquest.

"It would be wrong to suggest that a delay beyond the six-month target is necessarily in any way the fault of the coroner."