Further potential victims of "an evil serial sexual predator who preyed upon young men" have come forward following his sentencing, police have said.
Reynhard Sinaga lured 48 men from outside Manchester clubs to his flat, where he drugged and assaulted them.
On Monday, he was jailed for life with a 30-year minimum for 159 sex offences, including 136 rapes.
Police said a dedicated incident room for reporting sexual abuse has seen "a very positive response".
A spokesman for Greater Manchester Police said: "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."
Sinaga would wait for men leaving nightclubs and bars before leading them to his flat in Montana House, Princess Street, often with the offer of somewhere to have a drink or call a taxi.
He drugged his victims before assaulting them while they were unconscious, and filmed the attacks.
When the victims woke up many of them had no memory of what had happened.
Survivors Manchester, a charity that helps male survivors of sexual abuse, said the case "generates the ability to talk" about abuse.
Chief executive Duncan Craig said: "There are people ringing up who are not directly affected by this particular case, but are people who have been sexually assaulted, maybe even in childhood that are now feeling like the time is right to step forward and talk.
"It's something that we don't do enough of."
By Judith Moritz, BBC north of England correspondent
It was only when I listened to their individual stories in court that I began to understand the trauma experienced by Sinaga's victims.
The anguish of a student who'd dropped out of university as a result. Another who'd left his job. A third whose relationship had broken down. One who couldn't bring himself to talk about what happened to his family. And distressingly, another whose pain is so great, it drove him to contemplate suicide.
The publicity surrounding the case yesterday has been hard for them to endure. The media jointly agreed not to report it until after the Christmas break so that counselling services were fully in place for victims before it was made public.
Helplines set up for people affected have received multiple calls including some from potential victims.
Sinaga's convictions relate to crimes he committed from January 2015 to June 2017, but police believe he began offending years earlier.
Police say they have evidence the 36-year-old targeted at least 190 victims, but they have been unable to identify a further 70 victims and are now appealing for anyone who believes they may have been abused by Sinaga to come forward.
The Crown Prosecution Service said Sinaga was "the most prolific rapist in British legal history" as he was jailed at Manchester Crown Court on Monday.
Judge Suzanne Goddard QC described him as "an evil serial sexual predator who has preyed upon young men" who wanted "nothing more than a good night out with their friends".
Greater Manchester Police said anyone who believed they might have been attacked by Sinaga could report information online or call its police line on 0800 092 0410 from inside the UK or 0207 158 0124 from abroad.
The force said anyone in need of support from specialist agencies could call 0800 056 0154 from within the UK or 0207 158 0011 from abroad.
If you have been affected by the issues raised in this article, help and support can be found at BBC Action Line.