The gang associated with prominent Border republican Thomas “Slab” Murphy believe they were to be left alone as part of the peace process agreement, according to a source who has had official dealings with them.
The source said the gang feel “betrayed” by the targeting of their criminal activities.
It is expected that a significant tax bill will be served on Murphy by the Criminal Assets Bureau. About 20 proceeds- of-crime applications against assets associated with his group are pending in the High Court.
Murphy, of Ballybinaby, Hackballscross, Co Louth, is awaiting sentence after being found guilty by the Special Criminal Court last week of failing to furnish tax returns for nearly a decade from 1996.
Murphy and a group of about a dozen close associates believe the “architects of the peace process” assured them they would not be targeted in the wake of the 1997 IRA ceasefire, according to the source.
Sinn Féin leader Gerry Adams issued a statement at the weekend saying the hearing of the case before a non-jury court was a breach of Murphy's rights under the Constitution and the European Court of Human Rights.
Murphy was charged in November 2007 and took a case to the High Court contesting the decision to have his case heard by the Special Criminal Court. When he lost in the High Court, he appealed to the Supreme Court, which found against him in March 2014.
A charge of not filing tax returns would normally take a few hours of a court’s time, but Murphy challenged much of the evidence and his case lasted for 32 days. Three witnesses called by the prosecution offered evidence that differed from statements they had given to the Garda.
The charges covered the period 1996 to 2004. Any tax bill now issued will include interest and penalties.
While the court hearing involved Murphy’s income from farming, which he contested, the tax bill is expected to include alleged income from illegal activities such as diesel laundering.
A raid on the Murphy farm in March 2006 by officers on both sides of the Border found €630,000, made up of €435,000 and £150,000 in cheques, payment orders and cash.
The State seized the funds after the courts ruled they were the proceeds of crime. Murphy did not contest the ruling.
Information retrieved from burned laptops found at the time of the raid are understood to have yielded important information about the criminal enterprise.
Mr Adams, in his weekend statement, said Murphy contested the verdict of the Special Criminal Court and maintained his innocence.
The Special Criminal Court was established under powers contained in the Offences Against the State Act and has been criticised by Amnesty International, the Irish Council for Civil Liberties, and others.
The Minister for Justice and Equality, Frances Fitzgerald, earlier this year announced the establishment of a second court to deal with a backlog of pending cases.