Former members of defunct rockers Lostprophets said they were shocked and sickened when discovering their singer Ian Watkins was a paedophile.
The disgraced rock singer Watkins is currently serving a 35-year sentence for a string of child sex offences - including the attempted rape of a fan's baby.
His old bandmates - who have now formed a new group called No Devotion - said they had no idea of the vocalist's paedophile ways.
In an interview with Radio 1's newsbeat guitarist Lee Gaze said: " There was two sets of shock because there were the accusations - which was one thing.
"And then there was the actual, 'Yeah I did do it' which was a year later. He dragged that out for a year, so we got hit by it twice."
Bassist Stuart Richardson added: " Even though I was completely done with him (by this stage), I hoped it was all a mistake, he was innocent, he had to be.
"The first time, we knew the band was done. You can't go back from that."
Lostprophets' five remaining members - Lee Gaze, Mike Lewis, Stuart Richardson, Jamie Oliver and Luke Johnson - say they are now trying to move forward with their new band No Devotion - which is fronted by ex Thursday singer Geoff Rickly.
But the band admit they have to confront the past, before they can try and move on.
Gaze said Watkins' actions were still difficult to put into words.
Responding to questions about whether Lostprophets knew about Watkins' sex abuse, he added: " How could you know?
"Who would disclose such a thing to five people, who between them have eight children? You just wouldn't because they would be killed on the spot."
Towards the end of Lostprophets, Gaze said that Watkins had become increasingly distant from the band.
"He was doing his own thing," he added.
"That just grew worse over the years, the more he was using drugs.
"He could be in the same city as me and I wouldn't hang out with him, even if we weren't playing shows."
In the meantime, No Devotion are in the middle of recording their debut album and say they have been overwhelmed by the support they have been getting.
Rhythm guitarist Lewis said: "It was vindication almost that we were there and we are doing this and we do have an incredible support from people.
"It's been incredibly cathartic.
"It's time to move on and we just want to focus on that from here on in."
Dangerous sexual predator Watkins is currently serving a 29-year prison term - with an extended licence of six years - after pleading guilty to 13 sexual offences.
Earlier this month, he was refused application to appeal his sentence.