A former Catholic school teacher in country Victoria avoided jail on Thursday for a historical sex assault on a student in 1970.

John Skehan, 75, was given an eight-month sentence suspended for two years and was placed on the sex offenders register after he pleaded guilty to the indecent assault of his 13-year-old student at a boys school in Shepparton.

Victim Greg Barclay. Credit:Eddie Jim

That student was Greg Barclay, now aged 58 and a vice-president with the Australian Education Union.

Mr Barclay said outside court on Thursday that he was "gutted" with the sentence. Skehan had already been convicted and placed on a suspended sentence in 2010 for the indecent assault of a young child in Broken Hill in the 1970s.