Former butcher got his nickname from lucrative cigarette smuggling racket

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.
 

http://www.independent.ie/irish-news/news/former-butcher-got-his-nickname-from-lucrative-cigarette-smuggling-racket-34568565.html