Police believe more children could have fallen prey to paedophile Ian Watkins.
An international appeal has been launched for victims to come forward after concerns of at least two other child sex abuse victims in Germany and America.
British detectives are working with Interpol and the U.S. Department for Homeland Security after the 36-year-old Lostprophets frontman was jailed for 29 years today.
South Wales Police (SWP) believes that other children may have been abused in the years he toured with Lostprophets.
Senior investigator in the case Detective Chief Inspector Peter Doyle said: "Our priority area is Germany and the USA at the moment. The reason for that is that he travelled so extensively. Our view is that there are other victims," he said.
"The absolute number one priority is the identification and protection of children, protecting children wherever they are."
He said police were following leads in Germany and America adding that the lack of remorse shown by Watkins "potentially makes him the most dangerous sex offender I have ever seen."
Joanna Majic, 38, his former girlfriend, claims Watkins abused hundreds of young victims during years of drug-fuelled debauchery.
During sentencing today, Mr Justice Royce addressing Watkins, said: 'You had many fawning fans. That gave you power. You knew you could use that power to induce young female fans to help satisfy your insatiable lust and take part in the sexual abuse of their own children.
"I am satisfied that you are a deeply corrupting influence, you are highly manipulative, you are a sexual predator, you are dangerous.
"The public and, in particular, young females need protection from you."
The judge sentenced Watkins to 29 years in prison, of which he is expected to serve almost 20 years, followed by a further six years on licence on top of the nine years remaining of his jail sentence.