Police have appealed for possible further victims of Ian Watkins to come forward after the ex-Lostprophets singer admitted a string of sex offences.
They included attempting to rape a woman's baby in a case the lead officer called "the most shocking and harrowing child abuse evidence I have ever seen".
Detectives are continuing their investigation into the Welsh rock singer, 36, amid speculation there could be more victims in the UK and overseas.
Officers from South Wales, where he lived, have been working with agencies including Interpol, the NSPCC and the Department For Homeland Security in the US - one of the countries where Lostprophets toured.
Watkins also confessed to aiding and abetting another woman to sexually abuse her own child.
And he pleaded guilty to possessing and making indecent photographs of children as well as having extreme pornographic material involving bestiality on his computer hard drive.
He had faced 24 sex offence charges but admitted 11 at the last minute as his trial was due to begin at Cardiff Crown Court alongside the two women, who pleaded guilty to 13 offences in total between them.
Watkins is due to be sentenced in December
Lead investigator Detective Chief Inspector Peter Doyle said: "There is no doubt in my mind that Ian Watkins exploited his celebrity status in order to abuse young children."
He added Tuesday's "outcome does not mark the end of our investigations and we will work tirelessly to identify any other victims or witnesses and seek the justice they deserve.
"Above all this investigation has been focussed on the protection of children and my thoughts today are with those victims".
Watkins, from Pontypridd, will be sentenced on December 18 at the same court.
Meanwhile, a child expert has warned the sex abuse of young children is increasing in number and severity as the age of defenceless victims continues to go down.
Des Mannion, NSPCC Wales national head of service, spoke of his "horror" as the extent of Watkins' secret abuse was made public.
"The desire to sexually abuse small babies is something most of us find too horrific to comprehend," he said.
"However within the significant rise in the number of child abuse images being distributed online over the past year, agencies have noted both an increase in their severity and a significant decline in the ages of the children involved."