THE public inquiry into child abuse in state care is set to become the biggest and most expensive in Scottish history.

It was revealed yesterday that Scotland’s Child Abuse Inquiry (CAI) had already cost more than £600,000 in just two months and is predicted to dwarf previous high-profile hearings by millions of pounds.

Launching the first official call for evidence for the inquiry, chairwoman Susan O’Brien QC said: “Be clear from the outset that this is a complex inquiry and it will be expensive.”

One of Scotland’s largest inquiries, investigating C. difficile infections in the Vale of Leven Hospital, cost £10.7 million, while the Penrose inquiry into contaminated blood products cost over £12m.

With estimates based on inquiries elsewhere suggesting there may be more than 50 million pages of evidence to sieve through, a source close to the CAI predicted costs during the hearing’s four-year lifespan will eclipse all that have gone before.

Ms O’Brien has sought guidance from Australia where a Royal Commission of inquiry into child abuse has so far cost £267m.

She praised the quality of its work, insisting it was a “world leader in the sad science of getting evidence from survivors of abuse”.

The Scottish inquiry has a huge remit and will investigate incidents of physical and sexual abuse as well as emotional and spiritual distress suffered in both residential and foster care.

But it has proved controversial with some survivor groups who object to the fact that it will only cover those abused in residential care.

Laying bare the parameters of the investigation, Ms O’Brien said she would initially hold private hearings to enable abuse survivors to tell their stories before moving to public hearings.

Evidence given in both public and private sessions will be published, but names of both victims and their alleged abusers will be redacted initially.

The inquiry team will travel around Scotland and England to speak to those who apply to give evidence, in “small, quiet and comfortable” hotel rooms, she said. They may also take evidence from survivors abroad, including those sent from Scottish institutions to Australia, Canada or New Zealand, Ms O’Brien said.

Because the number of alleged abuse victims who intend to come forward is not known, the final cost of the inquiry cannot be determined but it is expected to run into tens of millions of pounds.

Ms O’Brien said she had already identified more than 290 organisations which may hold relevant documents.

Graeme Pearson MSP said the inquiry should be “thoroughly done” and no-one should “blanch from the scale of what we may or may not face”.

He said: “The inquiry has already cost a substantial amount of money to arrive at where we are now and that is nothing as yet. This is a once in a million inquiry and if it is going to be the biggest we have ever had we should make a proper job of it. We should not be worried about the scale and cost of it.

"Many survivors are angry and distressed by the way in which the government have gone about the process. The remit is overly restrictive and they don’t seem to want all the survivors to come forward and give evidence.”

Applications to give evidence will open after Easter and private sessions will begin to be scheduled from late April.

The inquiry will hear some evidence in "modules" Ms O’Brien said, to focus on particular institutions, individuals or topics and the first public hearings will be on the provision of psychological support for abuse survivors in Scotland. The inquiry will also commission universities to carry out research.

Ms O’Brien said recommendations would help make children who end up in state care in future safer.

“This inquiry is not just for survivors of abuse in the past, it is also for some Scottish children yet to be born,” she said.

And she added: “I am asking survivors to help us, by telling us what happened to them.

“In our final report we intend to provide an evidence-based analysis of what went wrong for so many children in Scotland for so many decades.

“The people who were abused are entitled to answers. How is it possible that so many institutions and authorities were blind to their suffering. Where was the protection of the law when they were raped or assaulted? Why did no-one in authority listen to them?”

Alan Draper, of the group In Care Abuse Survivors Scotland said the inquiry was long awaited: “Getting to this day is a positive in itself. But we have big unanswered questions about issues such as legal representation. Ms O Brien’s first point was about legal representation for the institutions and individuals accused of abuse. What about legal support for the victims? I am surprised she is so sensitive to the needs of the care provider organisations.”

Andi Lavery, of the group White Flowers Alba, which campaigns for victims of abuse carried out in institutions of the Catholic Church, said the inquiry was set up to be an ‘academic’ exercise. “We are laboratory rates in an academic study. They didn’t mention how this will deliver justice for victims,” he said.

However an NSPCC Scotland spokesman said: “Many victims of abuse have been waiting too long for an opportunity to speak out and we welcome the O’Brien Inquiry’s call for evidence. It’s vital that individuals who experienced childhood abuse or neglect while in care are able to talk about what happened to them. As a society, we need to learn from the past to prevent similar abuses from happening again.”