Sean O'Callaghan, who headed the Southern Command of the IRA before becoming an informer, said that for the first time since the formation of the Provisional IRA in 1970 there were "difficulties across every strand of the movement".
Mr O'Callaghan, who worked as a double-agent for nine years before handing himself over to the British police in 1988, also predicted continued tension in the province, regardless of any peace deal.
Mr O'Callaghan, who served eight years in jail before being given a Royal pardon for the information he provided, was interviewed on BBC's Today programme.
He said it would be wrong to assume that the so-called dissident elements within the Provisional IRA were necessarily that dissident.
He said the Continuity IRA, linked with recent attacks in the province, could be classified as quite dissident and its leadership would have serious differences with the leadership of the Provisional IRA. But he said another group, called the 32 Solidarity Committee, remained "within the republican movement".
When asked if he was suggesting that the IRA council was turning a blind eye, or actively encouraging the activities of those groups, Mr O'Callaghan said: "We know that for instance there have been a series of incidents which have come from the South Armagh area - and it's relatively common knowledge that the chief of staff of the IRA lives in South Armagh - he's controlled that area for more than 20 years.
"It's difficult to believe that a series of incidents can happen in that area without him being able to enforce his authority on it or without people feeling confident enough and strong enough to believe that they don't have to worry about him.
"The essential thing is that there have been a series if incidents coming from that area, and you would have imagined that if the IRA leadership wished to stop them then he is in an ideal position in fact to do so."
When asked for his predictions of what could happen if an agreement is reached in the Northern Ireland peace talks, Mr O'Callaghan said that whatever the result may be, the IRA response would be much the same.
"Whether or not there is agreement, the IRA will utilise the coming marching season and put pressure on unionists in that area.
"The IRA leadership will not go back to their old-style campaign. What they are engaged in is the politics of tension. You will get enough violence to make you aware of their existence and make you aware of their capability and enough to keep Northern Ireland in a constant state of unease."