Christopher Jarvis, 73, a former teacher at the now defunct St Peter’s boarding school in Seaford, East Sussex has been sent to jail.
Jarvis had previously been sentenced to eight years' imprisonment in 2013 for a series of sexual offences and received a further concurrent jail term in 2015 for gross indecency against a boy.
On 19 July 2017 Jarvis pleaded guilty to three charges of gross indecency with a boy under the age of 14 between December 1966 and July 1969, when the victim was aged between 11 and 13. Jarvis was sentenced to eight months' imprisonment for each of the three counts.
Kathryn Newman, a Senior Crown Prosecutor with CPS South East, said: "The defendant abused his position of trust as a teacher and perpetrated this abuse over a number of years against a child in his care.
"Although these crimes occurred in the late 1960s, we have been able to bring Jarvis to justice all these years later, as his victim was able to find the strength to report what had happened to him as a child."
Alison Millar, head of the abuse team at Leigh Day, said: “We now know that it can take many years for someone to disclose sexual abuse by a trusted adult, due to the ongoing impact of the abuse, which can have very long term effects. This case shows that our justice systems can accommodate this and deliver justice.”
If you have been affected by abuse the National Association for People Abused in Childhood runs a free support line on 0808 801 0331.