From early 2010 horrified fans who had become friends with Watkins went online to beg for help after discovering vile images on his computer.
Friends claim they called police to tell them the 36-year-old was a paedophile but officers did nothing, allowing him to go on to subject babies to the most horrific abuse.
A disturbing child porn profile created in that time by Watkins was viewed by more than 40,000 people on the internet and yet appears never to have been monitored by authorities.
In one post, written before his arrest, a fan wrote: ‘His on-off girlfriend reported him to police twice for being a paedophile.
‘He sent pornographic pictures of a little girl to a few girls telling them it was a five-year-old girl he’d raped. He also watches child porn constantly. Sick sick man.’
Watkins allegedly boasted to obsessed female fans that he had HIV and was on a mission to pass it on to children.
One fan added: ‘A girl found info on his computer on how to drug children. He told her he was thinking of giving kids drugs. He does need to be arrested before he infects anyone else.’
Watkins was only stopped late last year after South Wales Police raided his home on a drugs tip and stumbled upon his hard drives containing images, videos and conversations about him attacking children.
Yesterday police said he had taken vile pictures of children for as long as five years and may have many other victims across the world.
In August 2010 one fan wrote online that he had been grooming underage girls online.
Five months later, Watkins created a vile online profile, uploading 27 images of himself involved in depraved sex acts. The images were viewed more than 43,000 times.
He had also openly subscribed to groups on the site which contained images of child abuse.
Last night South Wales Police did not respond to questions about why they did not act sooner.
They vowed, however, to keep investigating in case there are more victims.
Watkins was described as a 'determined and committed paedophile' after he admitted attempting to rape a fan's 11-month-old baby son along with 10 other child sex offences.
Absolutely disgusting case, especially to fans of the band. As someone who grew up listening to their music, it makes me physically sick to see this.