Yousuf Raza Gilani faces contempt of court for his alleged non-compliance with earlier court orders [Reuters]

Pakistan's highest court has ordered the prime minister to reopen corruption proceedings against Asif Ali Zardari, the Pakistani president, in a Swiss court.

Yousuf Raza Gilani has been directed to write a letter to authorities in Switzerland that would reopen a case in which Zardari, the widower of former prime minister Benazir Bhutto, was previously found guilty in 2003 of committing graft amounting to at least $60mn dollars.

Zardari had appealed that decision, but Swiss officials dropped the case in 2008, at the request of the Pakistani government.

The Supreme Court has given Gilani until March 21 to file a compliance report.

The court also adjourned contempt proceedings against Gilani until that date. The prime minister was charged with committing contempt of court on February 13 for not complying with an earlier court order to reopen the corruption proceedings in Switzerland.

The Supreme Court has been asking the government to write to the Swiss to reopen the case since late 2009, when it revoked a political amnesty that froze legal proceedings against key politicians.

The amnesty, the National Reconciliation Ordinance, was deemed to be unconstitutional by the country's top court.

On Thursday, a seven-member bench headed by Justice Nasir ul Mulk directed Maulvi Anwar-ul-Haq, the country's attorney general, to communicate the order to Gilani.

Gilani's defence, as articulated by his counsel Aitzaz Ahsan, has been that he has never been directly ordered by the court to write the letter, and that the request has always been routed through the law ministry.

The law ministry, Ahsan contends, has always advised the prime minister not to write the letter, citing presidential immunity from prosecution as guaranteed by Article 248 of Pakistan's constitution.