Pakistan government has asked Switzerland to reopen graft cases against President Asif Ali Zardari related to the alleged stashing of 60 million US dollars in Swiss banks. The country's anti-corruption agency told the Supreme Court today that authorities had written letters to Swiss Attorney General and other officials to reopen the corruption cases that were closed under a controversial graft amnesty issued by ex-military ruler Pervez Musharraf. National Accountability Bureau Chairman Naveed Ahsan's lawyer Abid Zubairi informed this to a seven-member bench headed by Chief Justice Iftikhar Chaudhry. Mr Zubairi said the international mutual legal assistance that was granted to Switzerland in 1997 and subsequently withdrawn would be restored to facilitate the reopening of cases. The National Accountability Bureau, NAB, has taken steps to reopen 152 cases in which Zardari is named as an accused and the Foreign Ministry has been asked to cooperate in reopening the cases in Switzerland. The apex court had yesterday threatened to imprison the NAB Chairman after the government failed to meet a 24-hour deadline to reopen hundreds of graft cases, including those against Zardari and his close aides.