Almost 1,400 people have now come forward to say they were abused at Medomsley detention centre in County Durham.
Operation Seabrook is the Durham Police investigation into abuse allegations at the facility.
It was triggered after former prison officer Neville Husband was jailed for eight years in 2003 for abusing five youths.
It's been running for two-and-a-half years now and is the biggest of its kind. Officers have spoken to around 20 suspects.