Detectives investigating hundreds of allegations of sexual abuse in the north Wales care system have identified 37 potential suspects.
The National Crime Agency (NCA) said 28 care homes were under investigation as part of the inquiry ordered by David Cameron in November 2012.
In an update on the investigation, codenamed Operation Pallial, police said 255 people had reported one or more allegation involving offences against children as young as six between 1953 and 1995.
Police have been given the names or partial names of 120 potential offenders, and have formally identified 37 suspects.
"The number of people coming forward to report historical allegations of abuse in the care system in north Wales continues to increase," said Ian Mulcahey, the senior investigating officer.
"It is reassuring to know that individuals have had the confidence to come forward and we will fully investigate all information they are able to provide. In cases where people have contacted us but have declined to support further inquiries we will still ensure they receive any advice and support they need."
Detectives said there were potentially 61 repeat offenders among the 120 possible offenders, but cautioned that "this information requires further investigation for the information to be confirmed or excluded". Of the 61 individuals, 17 are believed to have died.
The NCA has arrested and interviewed 19 potential suspects, with one charged with a number of serious sexual offences.
Detectives said previously that they would continue to investigate allegations made against people believed now to be dead. In such cases, victims will be told whether their testimony is likely to have led to criminal charges being brought during the abuser's lifetime.
The investigation, which is being led by a team of 26 officers at the NCA's north-west headquarters in Warrington, cost £727,000 between May and November last year, police said.