It is turning into a major headache for the US president. Speculation is rife that senior White House staff, including George Bush’s closest aide Karl Rove, may face criminal charges over the leaking of a CIA agent’s identity to the press.A federal grand jury investigating the case is due to finish its hearings by Friday, but observers say there may be a decision today. Agent Valerie Plame’s identity was leaked after her diplomat husband, Joseph Wilson, accused the Bush administration of distorting pre-war intelligence on Iraq. The grand jury called on journalists to release their sources for the leak, jailing one who refused. The White House is sidestepping questions about Vice President Dick Cheney’s role in the case. Some media reports say he told his chief of staff, Lewis Libby, about the identity of Plame, weeks before her name appeared in a newspaper. Law professor at George Washington university, Jonathan Turley, had this to say about Cheney: “The vice-president faces a very serious situation and it seems to be getting more serious by the day.” In what would be a blow to the Whitehouse, experts say Rove and Libby risk charges of perjury or obstruction of justice, and would be expected to resign immediately.