On Friday, six out of 11 men standing trial in Aylesbury, Buckinghamshire were found guilty of large-scale sexual abuse of minors from 2006 to 2012. The convicted felons, mostly South Asian men aged from 29 to 45, are expected to be sentenced in September.
The Barnardo’s children charity regional director told the BBC it had worked with two of the perpetrators’ victims in 2008 and had taken up its suspicions with the authorities.
"At that time the agencies didn't respond in a way that we expected them to, although some actions were taken by the local authority so we escalated those actions further," Michelle Lee-Izu said.
One of the girls was sexually abused 60 men after being habituated into thinking it was normal behavior, according to the outlet.
The investigation into the sex ring was launched in 2013.
David Johnston, children services director at Buckinghamshire County Council, apologized on behalf of the council Friday for "letting [the girls] down during this period in their lives."
On Saturday, he told the broadcaster local authorities have "missed a number of opportunities to perhaps protect" the minors and provide additional services.