A scuba-diving instructor has been sentenced to life imprisonment for a series of indecent assaults on children and young people that he taught during a 11-year period, police said.

Philip James Gaisford, 64, an educational instructor, of Old Lane, St Johns, Crowborough, was convicted at Lewes Crown Court of 27 sexual offences, involving nine victims comprising of boys and girls aged between 13 and 18 between 1997 and 2008.

He was sentenced to life imprisonment and has been ordered to serve 12 years minimum before being eligible to apply for parole.

Detective Inspector Rob Morland, of Sussex Police, said: "Gaisford systematically and cynically abused trusting young people who had become involved with him in his capacity as a scuba diving instructor and the court clearly found his conduct to be a gross breach of trust.

"The investigation of this case was complex and I thank the witnesses for their courage in giving evidence.

"The verdict shows that if victims are willing to come forward, they will be supported to be able to give their evidence and justice can be achieved."