Peaches Geldof is under police investigation after she allegedly tweeted the identities of the two women who allowed their babies to be abused by Ian Watkins.
Geldof, daughter of Boomtown Rats singer Sir Bob Geldof, tweeted the names to her 160,000 followers after mistakenly thinking they had been released by the courts and seeing them published on several different US websites.
Victims of sexual abuse are guaranteed anonymity by law for life. The names of the two women who went on trial with the disgraced Lostprophets singer were never released in order to protect the identities of their children.
Geldof later deleted the tweets, but police confirmed they will be looking into the incident.
Det insp Peter Dolye, of South Wales Police, said: "We are aware that the names of Ian Watkins' co- defendants have been published on social media channels.
"Clearly, there is strong public feeling about this case and many people are using social media forums to talk about the issues involved.
"We are currently in consultation with the Crown Prosecution Service regarding the matter and will take action if appropriate.
Police previously warned people against discussing the Watkins case on social media in case they reveal the names of the victims or Watkins' two female accomplices.
Doyle added: "There is a very real danger that some of the detail being posted will lead to the identification of victims which will cause a great deal of distress to them and their families."
A spokeswoman for the Attorney General's Office said: "We understand that the names of the co-defendants in the Ian Watkins case were posted online but have now been removed.
"As has been previously reported, the co-defendants were the mothers of the victims.
"Victims of sexual offences have automatic lifetime anonymity and the publication of names or information which can lead to their being identified is a criminal offence. This is a police matter."
James Baines was recently handed a 14-month suspended jail sentence and ordered to pay £3,000 in costs after he tweeted images of a person he claimed was James Bulger's killer Jon Venebles as an adult.
Watkins pleaded guilty to 11 sex offences at Cardiff Crown Court, including attempting to rape a baby.
He was described as "a determined and committed paedophile" who exploited his celebrity status in order to abuse young children.