Former members of the IRA, MI5 and an undercover military unit may be prosecuted after an investigation into allegations of murder by an Army agent.
Freddie Scappaticci has denied being the agent codenamed Stakeknife.
He has also denied involvement in dozens of murders while a member of the IRA's internal security unit.
The officer leading the investigation said he believed there was enough evidence to charge former members of the IRA and the security forces.
Chief Constable Jon Boutcher, from Bedfordshire Police, has plans to submit files to the director of public prosecutions for Northern Ireland next year.
The investigation is known as Operation Kenova.
'All different sides'
"I am satisfied that I've got evidence that I'll be presenting... with regards to criminality of those that took people, abducted them and murdered them, and also with regards to offences where people tried to hide the truth," Mr Boutcher told the BBC.
"That submission of files, that process, will involve people from all the different sides of Operation Kenova, not one side or another.
"It will involve a number of people from different organisations."
Who is Stakeknife?
Fred Scappaticci is alleged to have been the most high-ranking British agent within the Provisional IRA, who was given the codename Stakeknife.
He was the grandson of an Italian immigrant who came to Northern Ireland in search of work.
He has admitted to being a republican but denied claims that he was an IRA informer.
He is believed to have led the IRA's internal security unit, known as "the nutting squad", which was responsible for identifying and interrogating suspected informers.
Mr Scappaticci left Northern Ireland when identified by the media as Stakeknife in 2003.
Mr Boutcher said his team had received significant levels of co-operation and information from former members of the IRA, MI5 and the Army.
"People who allowed their premises to be used by the IRA have spoken to us," he said.
"We have had members of the IRA talk to us, who were there when people were taken and tortured, and they've told us who did that.
"We've had members of the security forces speak to us and say records were removed to protect people from their criminality and from being investigated.
"We've had members of the security forces tell us that records were invented and created to protect people from their criminality."
'Evidence takes us'
The Operation Kenova team has interviewed 129 people, including an unspecified number of suspects from within the security forces and the IRA.
It has also gathered more than 12,000 documents, taken more than 1,000 statements and made 199 requests for new forensic DNA examinations.
"We are going where the evidence takes us, so that has meant speaking to those with links to government, the police, military, intelligence agencies and paramilitary organisations," added Mr Boutcher.
The officer appealed to anyone with information that could help the investigation to contact his team.
Freddie Scappaticci, 72, was sentenced this month to three months in custody suspended for 12 months after admitting possession of extreme pornography.