A paedophile priest dubbed a “sadist” by his victims has been jailed for at least nine years for luring schoolboys to his office with video games, cigarettes and alcohol before sexually abusing them.

Former Catholic cleric David Edward Rapson, 61, was found guilty of sexually abusing six boys at two Victorian boarding schools in the 1970s and 1980s.

In 2013 Rapson was jailed for 13 years, but was bailed 12 months later when the Victorian court of appeal quashed his rape and sexual assault convictions.

He was found guilty in three new trials in February and March this year.

In sentencing on Monday, county court judge James Parrish described Rapson as a sexual predator who took advantage of the trust he had as a teacher and spiritual adviser.

He said some of the aggravating circumstances of the abuse against the boys, who were aged between 11 and 16 at the time, bordered on sadistic.

The court heard one victim fell unconscious after Rapson gave him a lemonade, and woke up with Rapson on top of him. The abuse against one victim was so severe the boy required surgery on one of his testicles.

Many of Rapson’s victims had trouble maintaining relationships, some turned to drugs, alcohol and crime, victim impact statements revealed.

Parrish said Rapson’s defence lawyer, Shaun Ginsbourg, relied on arguments of mitigating factors, including that Rapson was raised by a physically abusive and alcoholic stepfather.

As a child he repeatedly ran away and sought refuge with two men who sexually abused him in exchange for protecting him from his stepfather.

Parrish said Rapson had undergone psychosexual therapy after being jailed on indecent assault charges in 1992 and again in 1993, and there was no evidence of reoffending since. But he had to take into account Rapson’s lack of remorse.

Parrish sentenced Rapson to 12 years and six months in prison, with a nine-year and four-month non-parole period. Rapson has already served 445 days in custody.

Outside court one of Rapson’s victims described Rapson as a sadist.

“He’s a sadist. Words can’t describe who he is. He’s just a pig,” he told reporters. “He had no remorse.”

He hopes he and other victims can start moving on and rebuilding their lives.