Martin Robert, who police say has been linked to Hells Angels activity. Police have issued an arrest warrant for Robert on suspicion of murder, attempted murder, conspiracy to commit murder, gangsterism and drug trafficking and conspiracy. Robert, 35, has been implicated in the killings of members of the rival Rock Machine and Bandidos biker gangs from 1994 to 2002 - the height of the biker war. He also has reputed ties to drug trafficking over the past 12 years, say police. Robert is believed to like vacationing in the Dominican Republic.