Britain's most prolific rapist spent 12 years drugging and assaulting young men -- until one woke up

Reynhard Sinaga was found guilty in four separate trials.

(CNN)The most prolific rapist ever caught in Britain, who spent more than a decade luring dozens of intoxicated young men to his apartment before drugging and sexually assaulting them, has been sentenced to life imprisonment after being found guilty in four separate trials.

Reynhard Sinaga was found guilty of 159 counts of sexual offenses against 48 different men, and must serve 30 years before he is considered for release. Police said the true number of his victims is likely to have been higher, having found evidence linking him to assaults on as many as 190 different people.
Details of his campaign of assault were suppressed while trials were ongoing, but can now be published.
    Sinaga, 36, approached men in the early hours of the morning outside nightclubs in Manchester, striking up a conversation and offering them somewhere to sleep or promising them more alcohol.
    Once he had brought them to his flat he would lace their drink with a drug -- most likely GHB, police said -- then film himself raping them while they slept. His comatose victims were unaware they had been assaulted.
    Sinaga's attacks only came to light in 2017, after an 18-year-old victim woke up at 6 a.m. while being assaulted. The victim managed to fight him off, and crucially was able to grab Sinaga's white iPhone before leaving the apartment.
    He went to police, who discovered 3.29 terabytes of graphic material on Sinaga's phone -- the equivalent to 250 DVDs. In some cases the assaults lasted hours, with one particular attack taking place for eight hours.
    Sinaga's victims, who were usually heterosexual and were often students, were seen snoring and in some cases vomiting while Sinaga raped them, Britain's Crown Prosecution Service said. When a groggy victim was starting to wake, Sinaga would push them back to the floor to continue his assault, or snatch away his phone to avoid suspicion.
    A photo of Sinaga's apartment where he raped dozens of men, released by Greater Manchester Police.