Teen 'disgusted' at being held with Lostprophets Ian Watkins
31 March 2014 Last updated at 08:25 BST
An 18-year-old who was in the local authority's "leaving care" system was held on the same adult wing as Lostprophets paedophile Ian Watkins.
Leon Meisl, who was previously in care, was transferred to the wing at Parc Prison, Bridgend, when he turned 18.
Meisl, who was in prison for burglary, went into care at the age of 12 and spent two months in Parc last year.
Children in care make up 1% of the population but a third of male young offenders are or have been in care, a charity has said.
Meisl said he was "disgusted" at being placed in the same wing as Watkins and Carl Mills, who was later convicted of murdering his daughter, girlfriend and her mother in a house fire in Cwmbran, Torfaen.
India Pollock spoke to Peter Johnson.