Gerry Adams was forced into his attack on the Special Criminal Court and his public backing of Thomas 'Slab' Murphy because of the republican movement's dependence on illicit funding, gardaí say.
Senior gardaí - those prepared to talk off the record - believe the IRA was given tacit permission to continue its massive "fundraising" activities as part of a secret deal with the British Government during the peace negotiations.
Although it has been consistently denied and there is no reference to it in any public documents, gardaí firmly believe a secret deal was done to stop the IRA carrying on its bombing campaign.
But the "blind eye" treatment allowed an enormous criminal empire to become established in the IRA heartlands of South Armagh and West Belfast.
The 'Republican Movement' - the IRA and its various other legitimate and semi-legitimate fronts - has assets of about a €1bn under its control, according to estimates by security sources. It operates on a financial system set up in the 1980s, whereby 25pc of the organisation's unknown and largely uninvestigated criminal income goes towards the day-to-day running of what is termed the 'Republican Movement'.
The other 75pc of its earnings are put towards building the financial and power structures of the organisation, as well as enriching its leading members.
Despite repeated claims that so-called 'dissident' republicans are largely responsible for the trade in smuggled tobacco, the bulk of which goes to the British black market, gardaí say that the trade is currently "totally controlled" by the Provisional IRA in South Armagh. The cigarette trade has brought the IRA into partnership with its former loyalist foes - with one well-known Ulster loyalist figure in Belfast said to be the contact for the IRA leadership in South Armagh responsible for buying and distributing illicit tobacco products in Protestant areas of the North.
The IRA simply used its former arms-smuggling routes to build its massive tobacco trade after the ceasefires of the mid-1990s.
Tobacco and diesel are and remain the traditional mainstays of the Republican Movement's fortunes.
Customs in Northern Ireland also estimated some years ago that as many as half the filling stations in Northern Ireland were buying and selling 'Provo diesel', and that fuel was also being sold through a large number of outlets in Britain and the Republic.
The last known evaluation of the Provisional organisation was carried out two years ago, when its assets were estimated to be worth between €800m and €1bn. The figure has almost certainly risen since then, sources say. It is this wealth combined with the power that the IRA still wields in its traditional heartlands that drives its ambition to create an Italian Mafia-style empire with its tentacles spreading into every potentially profitable area of the public and private sector in the Republic.
Gardaí say that Sinn Féin is the legitimate organisation that the Republican Movement is using to forge its way forward in the Republic.
If it gained a position in Government, it is feared that the IRA sleepers on the political front would be under Army Council orders to put in place structures that would give the organisation both legitimacy and even greater wealth and power.