British Prime Minister David Cameron's former spokesman Andy Coulson arrives in a van to Govan police station in Glasgow, Scotland May 30, 2012. Coulson was detained on Wednesday by police on suspicion of perjury after he denied in court any knowledge of phone hacking by reporters at Rupert Murdoch's News of the World. The detention of Andy Coulson, a former editor of the tabloid, damages Cameron because it calls into question his judgement in seeking to win Murdoch's backing by employing one of his most powerful journalists.REUTERS/David Moir (BRITAIN - Tags: POLITICS CRIME LAW)