The father of an Indonesian student described as Britain's most prolific rapist said his son's life sentence "fits the crimes", as the lurid case sparked shock and disgust in his native country.

On Monday, a judge in Manchester sentenced Reynhard Sinaga, a 36-year-old doctoral student, to life in prison and called him an "evil sexual predator" who preyed on drunken young men on nights out.

The court heard he may have attacked as many as 195 men, luring them into his flat with the offer of a place to stay or alcohol.

Sinaga was found guilty of 159 offences, including 136 rapes and eight attempted rapes, at four separate trials, according to the Crown Prosecution Service, making him "the most prolific rapist in British legal history".

"We accept the verdict. His punishment fits his crimes. I don't want to discuss the case any further," Sinaga's father Saibun told BBC Indonesia.

The family could not be immediately contacted by AFP.

The Jakarta Post reported that Sinaga was born in Sumatra's Jambi province but spent time in Depok on the outskirts of Jakarta.

Sinaga's case sparked outrage on Indonesia's huge social media platforms
Sinaga's case sparked outrage on Indonesia's huge social media platforms GREATER MANCHESTER POLICE / HO

He reportedly moved to Britain in 2007 to take a master's degree in sociology and later pursued a PhD at Leeds University.

Media reports said he was the eldest of four siblings who hailed from a wealthy Catholic family.

A University of Indonesia classmate said she was shocked at his crimes.

"He never misbehaved. He never even treated his friends with disrespect. That's why the news was such a shock to all of his friends," the woman, who did not want to be identified, told Channel News Asia.

"No one knew how this sweet, quiet, kind friend of ours turned into a monster capable of committing such heinous crimes," she added.

Sinaga's first trial began in mid-2018. The last ended last December. None could be reported until restrictions imposed to avoid prejudicing juries were lifted on Monday.

He is thought to have used sedatives to render his victims unconscious before filming the attacks. Most knew nothing about the assaults. He was caught only when one victim woke up.