The Police Ombudsman's report into collusion between police and loyalists in north Belfast said intelligence material, graded by the police as "reliable and probably true", linked the Mount Vernon Ulster Volunteer Force gang to 10 specific murders.
Peter McTasney was murdered on 24 February 1991.
The 26-year-old Catholic voluntary worker was shot dead by the UVF in the living room of his home at Bawnmore Park, Newtownabbey.
The report said Informant 1 was arrested and interviewed 19 times. It said his Special Branch "handlers" conducted the main interviews and claimed that notes were completed which did not reflect what happened in the interview. He was subsequently released without charge.
Sharon McKenna was visiting a Protestant pensioner
Sharon McKenna was murdered on 17 January 1993.
Described as a "Good Samaritan", she was shot dead while visiting a Protestant pensioner at his north Belfast home.
Two men called to the door and forced their way in when the pensioner opened it. They demanded the keys to Ms McKenna's car and, as she turned to lift them from the fireplace, they shot her in the back.
The report said a detective sergeant and a detective constable have both said Informant 1 admitted to being one of the gunmen involved in the murder.
It also stated that separate police documentation from the time also records "high grade" information that Informant 1 was involved.
It said authorisation was given by Special Branch to arrest Informant 1 on 19 January 1993, however despite this, he was still met by his handlers the following day, raising serious concerns about the integrity of this meeting.
He was arrested, detained for six days and interviewed 37 times. Some of those interviews were conducted by his handler.
Another of those officers present said he "felt like a gooseberry" sitting in on the interviews, as he knew that Informant 1 was a police source and would say nothing of relevance in front of him. Informant 1 was subsequently released without charge.
Special Branch increased their monthly payment to Informant 1 from £100 per week to £160 per week in the weeks after the murder, despite the fact that Informant 1 was a main suspect.
Sean McParland, 55, a father of four from south Belfast was murdered on 25 February 1994.
He was babysitting for his grandchildren at his daughter's house in Skegoniel Avenue when he was shot and wounded. He died a week later in hospital.
The report said investigators have seen information which indicated that two days before the murder, police received information from an informant that someone was to be killed the following morning.
They mounted a response at the relevant location during which they saw Informant 1.
Later that day, they received information that Informant 1 had been involved in the planned attack but that it was called off when police were seen in the area. Mr McParland was shot the following day.
The report added that investigators have seen additional information in which Informant 1 named another police informant as having carried out the murder. He also admitted to having had an involvement.
EAMON FOX AND GARY CONVIE
Eamon Fox was shot close to a building site in north Belfast
Eamon Fox, 44, a father of six and Gary Convie, 24, a father of one, both Catholics from County Armagh, were shot dead on 17 May 1994.
They were eating their lunch in a car parked close to a building site on North Queen Street in the Tiger's Bay area of Belfast when they were approached and shot.
The report said that the gunman who carried out the murders was said to have a "goatee" beard, and that when arrested for questioning, Informant 1 had a "goatee' beard, but was allowed to shave it off while in custody. No identity parade was held.
On 17 June 1994, Gerald Brady was murdered.
The 22-year-old Catholic father of two worked as a taxi driver. He was shot dead by the UVF after picking up two men in Antrim town centre.
The report said that police have intelligence which links Informant 1 and another police informant to the murder. Ballistic tests have also linked the gun used to Informant 1 and other police informants.
Thomas Sheppard was shot in a bar in Ballymena
Thomas Sheppard was murdered on 21 March 1996.
The 41-year-old Protestant was a member of the UVF from Coleraine.
He was shot in a bar in Ballymena. At the time, it was reported that he may have been killed by the UVF because they suspected he was an informer.
The report said investigators saw information which linked Informant 1 to the murder.
John Harbinson was murdered on 18 May 1997. He died after being handcuffed and beaten by a UVF gang on the Mount Vernon estate in north Belfast.
There were initial suggestions, reportedly from RUC police sources, that it may have been a domestic incident.
The report said that Special Branch had a "significant amount of high grade intelligence" about the four main suspects for the murder, including Informant 1, but did not pass on this information to the police officers investigating the murder.
It also said Special Branch had information that those who had carried out the murder had fled to a location in Ballyhalbert where they were "safely ensconced".
But again, they did not pass this information on to their police colleagues and forensic opportunities were lost.
RAYMOND McCORD JUNIOR
Raymond McCord jnr was beaten to death by the UVF
Raymond McCord Jnr was murdered on 9 November 1997.
The 22-year-old Protestant who had spent four years as a radar operator in the RAF was beaten to death by the UVF.
He had been a member of the organisation and is also said to have had some involvement in drugs.
The report said information held by police and corroborated from a number of sources, indicated that Informant 1, who was in prison at the time, ordered his murder and that another man, who was on leave from prison, carried it out.
It added that the ombudsman has established that there were a number of failures with the murder investigation which may have significantly reduced the possibility of anyone ever being prosecuted for the crime.
Tommy English was shot in a loyalist feud
Tommy English was a prominent loyalist in north Belfast and a former member of the UDP's talks team who was shot dead as part of a loyalist feud on 31 October 2000.
The report said investigators had seen information which linked Informant 1 to the murder.