In 2008 - long before he was sentenced on Wednesday to 35 years' imprisonment for child sex offences - former Lostprophets singer Ian Watkins, 36, admitted to an on-off girlfriend that he fantasised about assaulting children, reported The Straits Times.
The former lover, Joanne Mjadzelics, 38, said he spoke of "how he wanted to get me pregnant so that he could rape our daughter", reported the Daily Mail.
She said she reported him to the South Wales Police and told the child protection unit in his hometown, Pontypriddm, the name of a four-year-old girl he had bragged about abusing, added the report.
But she said a detective warned her that she could face harassment charges, after she wrote to alert Watkins' mother.
She was one of the former girlfriends, fans and informants who tipped off the police, but allegations as far back as 2008 were not investigated, apparently because officers were in awe of the rock star, said the Mail.
He was caught by chance, after the police arrested him for drug offences last December and found a video of him attacking a baby, added the report. Even then he was twice granted bail before being charged.
Watkins - who has dated television presenters Alexa Chung and Fearne Cotton - pleaded guilty last month to 13 charges, including trying to rape a baby. But he claimed that he had been high on crystal meth and could not remember the abuse.
Mjadzelics said the police failings had led to her former boyfriend becoming increasingly brazen and believing he was invincible, reported the Mail.
She claimed that he abused hundreds of young victims during years of drug-fuelled debauchery and that the true extent of his abuse might never be known because the mothers involved would not come forward.
Another former lover, who was not named, had told the police about the star eight times in four years, said the report. She passed on the names, ages and addresses of the toddlers he would go on to torture.
But she, too, was warned that she could be charged with harassment.
On Wednesday, two mothers of the children Watkins abused, who admitted child abuse charges, were sentenced to 14 and 17 years.
Both groupies, the women sexually abused their children when asked by the star and were prepared to make their children available to him for sex, the court heard.
One of the women, aged 21, started a sexual relationship with him around 2008 and he filmed their sessions, said the Mail.
He got rid of her when she had a baby with another man, but she got back into contact with the star after her relationship with the child's father broke down.
Together, she and the star video-recorded him trying to rape her 11-month-old son, said the report.
They exchanged text messages, planning a "summer of filthy child porn". The baby is now in foster care.
The other woman, aged 25, abused her baby daughter on camera for the star's pleasure after they began chatting online last summer, said the Mail.
He had written to the fan, who had 1,200 pictures of him, stating he was the "master" and "you and your daughter now belong to me".
They discussed "whoring out" the child to fat old men and torturing her for fun, said the report.
Watkins' stepfather, Baptist minister John Davies, spoke of the family's anger towards the singer on Wednesday. He told the Mail that he "could cheerfully spend an hour knocking him around a cell".
Watkins' biological father died when he was a child and he was brought up in his stepfather's clergy house, said the report.
When he was charged, his parents prayed he had been set up in a "complex conspiracy" by fans.
The truth has traumatised his stepfather and his mother, Elaine, who is unwell after a kidney transplant.
The stepfather told the Mail: "He was emphatic as he was growing up through his teenage years that he would never drink, never do drugs. That's what he told us. Whether that was to reassure us as parents, I don't know. But obviously something went wrong in later years."
He said the family believed the star had been damaged by fame.
They are hoping he can be rehabilitated and despite their anger, they will not totally cast him aside, the stepfather said.
"My heart aches for any individual who has been drawn into this and been affected by it. And only time will tell who those victims are."
The gallery below shows other stars who were recently involved in scandals.