A 79-year-old former music teacher has been found guilty of multiple non-recent sex offences against children.

John Clark, who had lived in Haslemere and taught at Aldro prep school in Shackleford, was charged with 26 offences against four boys aged between eight and 13 during a six-year period from the mid-1970s. He denied committing the offences against the schoolboys between 1975 and 1981 while he was music director at the school.

Clark of Thames Drive, Melton Mowbray, faces 20 years behind bars after being found guilty by a jury of 24 counts of indecent assault and one count of under age sex.

Commenting on his sentencing last Friday, Detective Constable Michael Chalk said: "The result demonstrates the depravity and severity of the abuse which Clark metered out to his victims.

“He used his position of authority and trust to groom the children who were pupils at the school where he taught. His victims included choristers, musicians and literary students.

“He duped them and their parents into believing he was a safe and reliable mentor, when in fact he was insidiously weaving his way into their lives before sexually abusing them. He would encourage the youngsters’ enthusiasm for music and on some occasions invited them to his family home or away on trips.

“He would became part of their lives, even visiting a pupil during the Christmas holidays to lure him away to further satisfy his abhorrent behaviour – he clearly had his own separate agenda and did not waiver from this over many years.”

A first complaint was made to police in 2002, when Clark was interviewed and denied the allegations. But he was arrested in December 2013 after three more victims came forward. The victims had buried their knowledge for years until they told their families and then the police.

Dc Chalk said: “I hope the sentencing will give closure and go some way in helping his victims move on with their lives.” He said the trail had been “particularly harrowing” for the victims, as they had to hear how their abuser claimed the offending was caused by another teacher at the school – a man who is now deceased.

Dc Chalk added: “They are to be commended for their courage and fortitude in coming forward and pursuing this prosecution after many years. This has been a lengthy investigation which has been bravely supported by the victims and I would encourage any victim to come forward to Surrey Police and report any similar incidents.

“Surrey Police treats all allegations of sexual abuse, whether recent or non-recent, extremely seriously.

“Our priority is victim care and people need to feel confident that if they come forward and report an offence, we can help. We have a dedicated investigation team for such crime and the dedicated unit works to obtain best evidence.”