A girl was given two sexually transmitted infections by her paedophile foster parent just weeks after being taken into care because of sexual abuse at home
The 7-year-old had already been abused, aged 6, by a 32-year-old man who was friends with her brother while she was in bed with her mother, according to the Daily Mail.
The girl then suffered more abuse when she was looked after by two newly approved foster carers, contracting gonorrhoea and chlamydia.
A serious case review by Croydon Safeguarding Children Board in South London warned lessons had to be learned to avoid other children suffering a similar fate.
The girl, named Claire in the report, went to school "splay legged" after her first night staying with the foster carers, according to the Croydon Advertiser and 15 months later a test showed the girl had two STIs.
Her foster mother also tested positive for gonorrhoea and her foster father had chlamydia.
It is believed the male was successfully prosecuted for the abuse, but Croydon Council declined to reveal his sentence.
The report found there were failures in communication, problems with newly qualified staff and their managers and insufficient assessment of foster carers.
One finding seen as particularly worrying was that Claire was kept at the foster carers' home even when a doctor had expressed concerns she could have an STI.
CSCB independent chair Sarah Baker, said: "All [staff], without exception, believed at the time of this incident they were providing Claire with a safe and secure home.
"The review found no evidence that anything at the time could have indicated this foster carer was likely to sexually abuse a child in his care.
"However, there are still lessons to be learned and actions were immediately taken to tighten up a variety of processes."
Claire's maternal family, who gave her up "to be cared for by the state", told how they were "deeply distressed" by revelations of how she had suffered.