[4] In December 2015, Murphy was found guilty on nine counts of tax evasion following a lengthy investigation by the Criminal Assets Bureau of the Republic of Ireland.
Murphy was involved in smuggling huge stockpiles of weapons from Libya in the 1980s[8] and was a member of the Army Council that decided to end its first ceasefire with the 1996 Docklands bombing in London that killed two men.
[9] Accused by the Sunday Times of directing an IRA bombing campaign in Britain, in 1987 Murphy unsuccessfully sued the paper for libel in Dublin.
[9][11] The Sunday Times subsequently published statements given by Adrian Hopkins, the skipper who ferried weapons from Libya to the IRA, to the French authorities who intercepted the fifth and final Eksund shipment.
Hopkins detailed how Murphy met a named Libyan agent in Greece, paid for the weapons to be imported, and helped unload them when they arrived in Ireland.
[14] It was extensively reported in the media that the investigation was aimed at damaging the suspected multi-million-pound empire of Murphy, who according to the BBC's Underworld Rich List, has accumulated up to £40 million through smuggling oil, cigarettes, grain and pigs, as well as through silent or partial ownership in legitimate businesses and in property.
Furthermore, Murphy claimed that he had to sell property to cover his legal fees after his failed libel case against the Sunday Times, and that he made a living from farming.
He's a good republican and I read his statement after the Manchester raids and I believe what he says and also and very importantly he is a key supporter of Sinn Féin's peace strategy and has been for a very long time.
"[21]He also said: "I want to deal with what is an effort to portray Tom Murphy as a criminal, as a bandit, as a gang boss, as someone who is exploiting the republican struggle for his own ends, as a multimillionaire.
"[23]Murphy was arrested in Dundalk, County Louth on 7 November 2007 by detectives from the Criminal Assets Bureau, on charges relating to alleged revenue offences.
In March 2013, the Garda and the PSNI, along with members of the Irish Customs Authority and HMRC, raided Murphy's farm on the Louth-Armagh border.
[27] There were serious concerns within the Garda and PSNI that a mole may have tipped off Murphy about the raid hours prior to it, as "Laptops, computer disks and a large amount of documentation had been destroyed in the fires."
[28] On 17 December 2015, Murphy was found guilty on nine charges of tax evasion by a three-judge, non-jury Special Criminal Court trial sitting in Dublin, lasting nine weeks.