Britain's Attorney-General's office has announced an inquiry into social media messages that may identify child killer Jon Venables.
The posts would be breaking a worldwide injunction on identifying Venables or his co-defendant, Robert Thompson, according to the Daily Telegraph UK.
The pair murdered 2-year-old James Bulger in Liverpool in 1993.
They were released in 2001 with new identities protected by a court order, preventing anyone from publishing photographs of them or information that could lead to them being identified.
The order also covers material that is purported to show them, even if it is not actually them.
In 2013 two men received suspended sentences for contempt of court after posting photographs on Twitter said to show the two.
Now new messages are said to have been posted on social media sites that might identify Venables.
A spokesman for the Attorney General's Office said: "We have received a complaint that the anonymity order has been breached and we are investigating it."
Other online messages seem to show the location of Maxine Carr, former girlfriend of Soham murderer Ian Huntley, the Guardian reported.
The Attorney General's office said it had not received a complaint relating to her case but would investigate if it did.
Carr was also granted a new identity after her release from prison in 2004 after giving her then-boyfriend Huntley a false alibi for the day Soham schoolgirls Holly Wells and Jessica Chapman went missing.
Huntley was later convicted of their murder.
Only one other former prisoner has lifelong anonymity - child killer Mary Bell.
Attorney-General Jeremy Wright, QC, this year said contempt of court laws were out of step with the modern world and needed to catch up with the social media age.
Speaking to the Daily Telegraph, he said members of the public "don't understand what the Contempt of Court Act says, and probably don't realise what damage their piece of social media commentary or comment might do".