Former butcher got his nickname from lucrative cigarette smuggling racket
Noel 'Kingsize' Duggan (57), originally from Cabra in Dublin, is a convicted burglar and a lifelong pal of Gerry 'The Monk' Hutch.
Duggan had originally been a butcher before opting to get involved in organised crime, specialising in smuggling and fencing stolen goods.
Duggan gained his nickname and became a millionaire because of his massive involvement in cigarette smuggling.
He was for many years classified as a member of the criminal gang centred around 'The Monk', who masterminded some of the country's biggest robberies.
Duggan had also been involved in laundering money for the gang by buying up several properties around the city.
He had several convictions for receiving stolen goods, forgery and burglary but had not come to garda attention for years.
For several years, he operated a thriving cash and carry business on Queen Street in Dublin's north inner-city, which he used as a cover for his smuggling operation.
He made a fortune from Ireland's illegal cigarette trade and was regarded by gardaí as the biggest single wholesaler of illicit tobacco in the 90s.
His racket in smuggled cigarettes was so big that the retailers representative group RGDATA complained to the government that their members were losing huge amounts of revenue as a result.
In 1996, a Garda operation - Operation Nicotine - was launched to target Duggan's multi-million pound business.
He was targeted by the Criminal Assets Bureau (CAB) and served with a tax assessment of €4m.
He was eventually forced to hand over the keys of several inner-city properties to CAB, which were auctioned off to pay a final settlement of €2m.
In 2003, the CAB confiscated a five-storey apartment and retail block owned by him.
However, gardaí believe he remained heavily involved in the illegal cigarette trade and worked with ex-Provos based in the border area.
It is understood that he became a primary target for the Kinahan cartel because of his long-standing business and personal relationship with their arch enemy, 'The Monk.'
In recent years, Duggan was regularly spotted in the company of Gerry Hutch and the pair were said to be as "close as ever".
He often travelled to Hutch's base in Lanzarote.
Sources said last night that Duggan remained heavily involved in the illegal cigarette trade all over Ireland.
Like Hutch, Duggan was not involved in the drugs trade.
Duggan was previously involved in a bitter dispute with exiled crimelord John Gilligan after Gilligan's release from jail in 2013, but that is not believed to be the reason for last night's murder.