Detectives investigating historic allegations of child abuse at North Wales care homes said the number of alleged victims and care homes involved are much higher than previously thought.
Operation Pallial, the inquiry launched last November, has received 140 allegations relating to 18 care homes between 1963 and 1992, including fresh claims by 76 new complainants, a progress report released today has shown.
North Wales Police warned offenders they should "live with the knowledge that we will always examine new information and evidence and seek to bring them to justice for their crimes".
The director of the NSPCC Helpline has applauded today's update on the inquiry into historic allegations of child abuse in North Wales.
Peter Watt said, "This investigation is a major step forward into probing claims of widespread child abuse".
"Many who have been waiting decades for justice and for their voices to be heard have now finally found the courage to come forward and we mustn't fail them this time", Mr Watt continued.
"This is potentially another sad chapter of child abuse following the devastating revelations of the Savile investigation and shows we all have to remain vigilant to protect vulnerable children".
The NSPCC is providing a dedicated round-the-clock helpline - 0800 389 6176 - which has already received 124 calls relating to this inquiry.
– North Wales Chief Constable Mark Polin
If you believe that the passage of time will reduce the resolve of Operation Pallial or any police force to identify people still alive who have caused harm to others and bring them to justice, you are are sorely mistaken.
People who commit serious and sexual offences should live with the knowledge that we will always examine new information and evidence and seek to bring them to justice for their crimes.
Offenders should quite rightly have to look over their shoulders for the rest of their lives.
Operation Pallial is being conducted by the National Crime Agency, at the request of North Wales Police, to ensure its independence.
North Wales Chief Constable Mark Polin said he had asked the NCA to continue the work to phase two.
I took the decision to ask the NCA to investigate these allegations, conscious that some victims of historic abuse may not have the necessary level of confidence in North Wales Police to report matters directly to us.
Pallial has now secured accounts from almost all victims who are willing to support an investigation and it makes absolute sense for the officers and staff involved to be at the core of phase two and to move matters forward as quickly as possible.
Phase two will involve further investigations, he said, in liaison with the Crown Prosecution Service.
Detective Superintendent Ian Mulcahey , the senior investigating officer, said: "These are serious allegations that will be thoroughly investigated.
"Many have provided graphic accounts of abuse, in some cases of very serious criminality."
Detectives reinvestigating claims of historic child abuse in North Wales have received 140 new allegations since November, a progress report on the inquiry showed.
A public report on Operation Pallial revealed there had been 76 new complainants making allegations of historic child abuse linked to 18 care homes across North Wales.
The alleged offences, against boys and girls aged between seven and 19, are believed to have taken place between 1963 and 1992.
It is claimed a total of 84 individuals, 75 male and nine female, were responsible for the abuse and of those 16 have been named by more than one complainant.
North Wales Police have asked Keith Bristow, National Crime Agency, to continue an independent investigation into the allegations.