Harry Fitzsimons is currently held in Rebbibia prison, Rome's highest security prison, accused of involvement in a £390m money laundering racket in southern Italy.
He denies all wrongdoing.
The racket, which involved holiday apartments in Calabria and left many investors out of pocket, has been linked by Italian investors to the Ndraghenta, a powerful Mafia-style organisation based in the region.
It was the subject of a BBC Spotlight expose last night which interviewed Belfast woman Roisin Adams who paid £100,000 for two apartments.
Mr Fitzsimons, who got a commission on each sale, was not found in the initial swoop code named Operation Metropolic on March 16 but was extradited from Senegal to Italy in August.
He first came to public notice after he carried out the bombing of the Woodburn House hotel in 1971. At his trial he was described as one of the IRA's most senior officers. As soon as he was released from prison 10 years later he started renovating houses and, he says, cut his links with the IRA while remaining a republican politically.
He subsequently built up a property empire in Belfast, and was well known as the proprietor of Rumours nightclub. In 2006 he sold a garage and shops on Belfast's Stewartstown Road, which netted him £2.5m.
Mr Fitzsimons says he transferred £1m of it to Calabria to take part in the beachfront developments and lived there between late 2006 and 2012.
Last March Nicola Gratteri, an Italian investigator, described Mr Fitzsimons as “a middle-man delegated by the IRA to recycle the proceeds of terrorist activities and to reinvest the financial resources of the movement”.
Mr Fitzsimons had previously been investigated by authorities in the Republic and Northern Ireland for money laundering but not convicted.
Mr Fitzsimons says he has done nothing wrong. He told the Belfast Telegraph in March that he had formed his company to promote a development called Jewel of the Sea after being put in touch with the developer, Antonio Cuppari, by an estate agent.
According to Spotlight the Italian police regard Cuppari as a senior member of Ndraghenta. The investigation is linked to the cases of up to 74 Northern Ireland families who claim they have been scammed into making payments for holiday properties which never materialised.
Spotlight revealed that €6.5m (£5.4m) in total was tracked to a company controlled by Harry Fitzsimons and his partner Antonio Velardo’s company in Cyprus.