An inquiry is under way after a teenager on the sex offenders' register sexually abused a boy six years younger than him.
The investigation was ordered after the 16-year-old was arrested for a number of rapes on his 10-year-old victim.
In Cardiff Crown Court the defendant, who cannot be named, admitted six charges of rape and two of sexual assault against the boy, from the Vale of Glamorgan, south Wales.
He was subsequently detained indefinitely under the Mental Health Act during sentencing last month.
During the hearing it was disclosed he had been convicted at a youth court in England of inciting a male child into sexual activity four years earlier.
For that offence he received a 10-month referral order and was placed on the sex offenders list for two and a half years.
A review is now under way to see if there are any lessons to be learnt from what happened.
One of the agencies charged with monitoring the teenager after his family moved to Wales was the Vale of Glamorgan council.
They were heavily criticised in a report over another case in which a teenage paedophile was placed with a foster family whose children he went on to abuse.
Beverley Noon, the operational manager for the Vale of Glamorgan Council, said the two cases did not bear comparison.
"We sympathise with the family and the circumstances in which they find themselves," she said.
"However, this is a multi-agency issue, not a matter for the Council alone.
"It is totally inappropriate to compare the circumstances of this case with the recent social services incident.
"As a member of the Local Safeguarding Children's Board (LSCB) the Council is co-operating fully in reviewing what happened in 2006 and 2007, as are other local agencies.
"Neither the young person nor the victims were social services clients. The young man came to the attention of the Council's Youth Offending Service (YOS) in September 2006 as a result of the imposition of a referral order by a youth court for a minor sexual offence which occurred in 2004.
"As he was a registered sex offender, he was also the subject of arrangements managed by the police.
"The young man was a client of the YOS for a ten-month period on a referral order until July 2007. As the 2004 offence was of a sexual nature he was referred to a specialist service for young people. The conclusion of their assessment in June 2007 was that further intervention was unnecessary and that he did not require anything other than the current level of support and supervision being offered to him by the YOS.
"He completed the period of supervision as required in July 2007 and the Council's involvement ceased.
"When the YOS became aware of the subsequent charge by the police in 2008, the Youth Justice Board was informed of the circumstances.
"There were no criticisms by the judge in the court case of the council or other local agencies.
"The multi agency review is nearing completion and the results will be considered by the Local Safeguarding Children's Board and all constituent members in due course."Reuse content