A sex abuse scandal at a detention centre could cost up to £12 million in compensation pay-outs, a solicitor for many of the victims has said.
More than 140 people claimed they were abused as youngsters in Medomsley Detention Centre in the 1970s and 1980s and Durham Police has received more calls since a TV documentary was broadcast this week.
They had no escape from staff who subjected them to sexual and physical abuse while they were behind bars for crimes which today would often receive a community punishment.
Guard Neville Husband was jailed in 2003 for committing sex attacks on youngsters. Accomplice Leslie Johnson, a store man at the centre, was also jailed. They have since died.
One trainee was sexually abused after having a bread knife held to his throat, another attacked after he stole marzipan and icing from a store.
Solicitor David Greenwood, a specialist in the rights of survivors of sexual abuse, represents 53 people who claim they were abused at Medomsley.
He said: "If everyone comes forward and pursues civil compensation claims it could cost £8m-12m.
"That is not taking into account the cost of the police investigation and any public inquiry.
"It is going to be an expensive business for the Government."
Mr Greenwood, based in Wakefield, West Yorkshire, praised Durham Police's "progressive" investigation, which could stretch well into 2015.
"The mechanisms they are putting in place to support survivors who are describing for the first time what happened, and obviously are vulnerable, are really encouraging," he said.
"I hope that the inquiry into Medomsley becomes a template for inquiries into institutional abuse."
Mr Greenwood became involved in the case when Husband was prosecuted and said others knew what was going on at the time, and one staff member even admitted he "felt sorry for the boys".
Mr Greenwood said: "The question has to be asked, why was there no system in place for that to be reported and investigated?
"I don't know the answer to that question.
"It appears there was a culture of being able to treat these young trainees exactly as officers liked.
"You have to understand the impact on the boys, they were locked up and could not escape from it, which is doubly traumatising."
A Ministry of Justice spokesman said: "The outcome of the ongoing police investigation will be considered in due course. It would be inappropriate to comment further at this time."