The commission monitoring paramilitary activity is expected to support the chief constable's assessment that the IRA was behind the alleged abduction of a dissident republican.
The commission arose out of discussions on the joint declaration
The Independent Monitoring Commission's (IMC) first report is to be published on Tuesday.
It is also understood to have recommended financial sanctions against Sinn Fein and the Progressive Unionist Party (PUP) rather than exclude them from the political institutions.
The PUP is aligned with the outlawed Ulster Volunteer Force, which has been blamed for recent racist attacks in Belfast and the murder of John Allen in Ballyclare, County Antrim, in November last year.
The IRA, the Irish National Liberation Army (INLA), Ulster Volunteer Force (UVF), Ulster Defence Association (UDA) and Loyalist Volunteer Force (LVF) are understood to be mentioned in the report.
It is believed it will cover a wide range of the organisations' activities, including all acts which break the law.
The commission, which began operation in January, was originally due to report on loyalist and republican ceasefires every six months.
This timetable was dramatically altered in February following an incident involving Bobby Tohill, which Chief Constable Hugh Orde immediately blamed on the IRA.
Meanwhile, one of the four men charged with the attempted kidnapping of Bobby Tohill is making a legal challenge to stop the report being published.
His lawyer claimed the report would prejudice his trial.
Speaking on Monday, Hugh Orde said that the IMC would not be relying solely on security sources.
"They have been briefed by many people, not just security services, I know they have been out and about speaking to many sorts of groups, community groups, political groups," he said.
"I think what they will pull together is the big picture if you like, perceptions of terrorism from all sorts of different dimensions into one report."
However, Sinn Fein has said it will not accept any sanctions imposed on it as a result of the commission's report.
Speaking on BBC Radio Ulster on Monday, Sinn Fein assembly member Alex Maskey said he believed the report was being used to influence political negotiations.
"We will not be accepting these sanctions if they are to be imposed upon our party, although we may not be able to do much about them, at least initially," he said.
The body will report back on the state of the ceasefires
However the deputy leader of the DUP, Peter Robinson, described any threat of a financial penalty as inadequate.
"If they are simply saying that the going rate for a murder or an attempted murder is a financial penalty, I don't think that will go down with the public and I don't think the public will accept that," he said.
Alliance Party leader David Ford said he believed the report would "shine the spotlight of reality on what is happening".
"By telling the truth they will actually give great encouragement to the great majority of people in this society," he said.
The four-man commission is a crucial element in the two governments' plans for restoring devolution, which was suspended in October 2002 amid allegations of IRA intelligence gathering at Stormont.
Following the Tohill incident, Secretary of State Paul Murphy said it amounted to a serious breach of paragraph 13 of the governments' joint declaration.
This document was produced last year as an attempt by the British and Irish Governments to move the political process forward and paragraph 13 demands an end to paramilitary activity.
Following Mr Murphy's statement, the IMC report was brought forward, first to May and then to April.
Paul Murphy: Holding talks with main parties
The IMC has the power to recommend sanctions, but only in the context of the devolved institutions operating normally.
The governments hope to hold intensive proximity talks chaired by the two prime ministers in London before the end of the month.
No mechanism exists to exclude parties from these talks.
The commission is comprised of Richard Kerr, a former deputy director of the Central Intelligence Agency; Commander John Grieve, former head of the Metropolitan Police's anti-terrorist squad; Lord Alderdice, the former Speaker of the Assembly and retired Irish civil servant Joe Brosnan.
Another function of the commission is to scrutinise the government's programme of demilitarisation and complaints about political tactics which threaten the stability of the devolved institutions.
However, only the British Government's nominees - Lord Alderdice and John Grieve - examine how devolved ministers and Northern Ireland parties are honouring their commitments under the Good Friday Agreement.
The commission arose out of discussions on the joint declaration involving London and Dublin and the political parties.