More alleged victims have come forward to claim they were attacked by Britain's most prolific rapist, police have confirmed.
But it is feared the Indonesian born student could have many more victims, who are yet to report offences to the police.
Following the announcement of Sinaga's conviction, Greater Manchester Police (GMP) set up a dedicated helpline and just 24 hours later the force confirmed that more men have already come forward to report attacks.
A spokesman for GMP said police said the incident room for reporting sexual abuse had seen "a very positive response".
The spokesman added: "For operational reasons we are unable to give out specific numbers of calls made to the incident room or information made online via the Major Incident Public Portal at this time.
"However, we can confirm that some of these reports relate to potential further victims of Sinaga."
But it also feared the 36-year-old, who came to the UK in 2007, could have been raping strangers for years before he began filming the attacks in 2015.
Sinaga would approach his victims in the bars and clubs close to his central Manchester apartment, striking up a conversation with those who looked most drunk and then inviting them back for a drink.
Once he had lured them to his flat he would spike their drinks with the date rape drug GHB and when they were unconscious would rape them often repeatedly.
When they came round the following day, the vast majority of Sinaga's victims were completely unaware they had been attacked and some even thanked him for looking after them.
But his reign of terror came to an end in June 2017 when one of his victims woke up during an attack and managed to fight Sinaga off and report him to the police.
When detectives examined Sinaga’s mobile phone they discovered a vast cache of disturbing film footage chronicling his offending.
Following his arrest Sinaga maintained his innocence, insisting all the liaisons were consensual and his victims had been playing dead as part of a sex game.
He was convicted of all offences and on Monday was jailed for life with a minimum tariff of 30-years.
:: Anyone wishing to make a report to the police relating to Sinaga is asked to contact: 0800 092 0410 (calls made from within the UK) / 0207158 0124 (international calls).
Reports relating to Reyhard Sinaga can also be made online via the Major Incident Public Portal: https://mipp.police.uk/ operation/06GMP19V24-PO2