Defrocked priest David Rapson has been sentenced to 12 and a half years in prison for the rape and indecent assault of six boys in Victoria during the 1970s, 80s and 90s.

The Melbourne County Court heard the boys were as young as 11 or 12 when Rapson abused them at the Catholic boarding school he taught at.

The judge described Rapson as a "sexual predator seeking sexual fulfilment at the expense of young boys".

He said Rapson displayed "cruelty and violence bordering on being sadistic".

Rapson will be eligible for parole in 2023.

One of Rapson's victims, who wanted to only be known as his first name Ben, said the verdict represented closure for him.

"I'm glad it's finally over. It's taken a big toll on us all and hopefully it's the last of it and we can move on as best we can," he said.

"It's impacted my life in a big way - crime, drug abuse, things like that - and because he held the position he held in the church I couldn't tell my parents or anyone like that what happened until probably four years ago.

"He's just a sadist, a disgusting person and human being."

Retrial follows miscarriage of justice

The former priest was jailed last year for 13 years for the abuse of eight boys, but the Victorian Court of Appeal quashed those convictions on the grounds that the charges should have been prosecuted separately.

There were eight complainants heard in a single trial, but the DPP acknowledged that significant parts of the evidence were not "cross-admissible", or able to be heard by the same jury fairly.

The DPP said this prevented Rapson from receiving a fair trial.

Rapson faced fresh trials in the Victorian County Court, after prosecutor Peter Kidd SC told the appeal court he should face three separate trials on the charges.

But Rapson's barrister Paul Holdenson QC argued there should be separate trials for each of the eight victims.

The retrial covered the abuse of six victims.