Palermo, July 11 - Police in Palermo arrested three suspects Thursday in the brutal murder of Enzo Fragala', a former MP for the now-defunct right-wing National Alliance (AN). Two of the suspects, Francesco Arcuri and Salvatore Ingrassia, are linked to the Cosa Nostra mafia and already serving sentences for other crimes, police said. Fragala' died in hospital on February 2010 three days after he was viciously beaten with a blunt instrument while leaving his office here. The former lawyer was attacked from behind by a man wearing a motorcycle helmet, which completely covered his face, according to descriptions made at the time of the attack Investigators initially were convinced the motive for the attack was more related to Fragala's work as an attorney than his activities as a politician and at first ruled out any mafia connection. Police said Thursday that according to a State's witness, Monica Vitale, who had a relationship with a mobster, Fragala' was killed because he bothered the wife of a client. Investigators also suspect his work may have ruffled mafia feathers elsewhere. While in parliament Fragala' served in the House justice committee. His AN party was broken up in 2009 to form part of the People of Freedom (PdL) party of three-time premier Silvio Berlusconi.