A member of Melbourne's orthodox Jewish community who raped a 15-year-old boy and sexually assaulted eight other boys has been sentenced to spend eight years in jail.

David Samuel Cyprys, 45, was a security guard, locksmith and leader of young people at the Yeshivah Centre and College in St Kilda East when he raped the boy five times between 1990 and 1991.

Jailed: David Cyprys worked as a security guard at the Yeshivah Centre. Credit:Jason South

While a member of the Yeshivah community he also molested eight boys as young as seven over an eight-year period.

Cyprys was found guilty of five counts of rape at a trial in August and then pleaded guilty to a further 12 charges, including five counts of indecent assault and four of procuring an act of gross indecency.