Islamabad: In a major setback to Pakistan's embattled leadership, the Supreme Court on Friday ordered a time-bound investigation into the memo scandal, overriding the government's contention that the issue should be probed by a parliamentary panel.

A nine-judge bench led by Chief Justice Iftikhar Chaudhry gave its ruling after hearing arguments by the government's law officers and several petitioners, including opposition PML-N chief Nawaz Sharif, who had asked the apex court to probe the 'Memogate' scandal.

"The court has established a commission for the investigation into the memo case. The Chief Justice of the Baluchistan High Court will lead this commission," Attorney General Maulvi Anwar-ul-Haq told reporters outside the court.

The three-member commission was asked to complete its probe within four weeks.

"The Commission shall be exercising all the powers of judicial officers for the purpose of carrying out (the probe) and it shall be free to avail services of advocates, experts of forensic science and cyber crimes," the apex court said in its order.

The apex court directed all federal secretaries, including the Interior Secretary, Cabinet Secretary and Foreign Secretary, the Chief Secretaries of all provinces, the head of the Federal Investigation Agency, provincial police chiefs and Pakistan's envoys to the US and Britain to provide assistance to the commission.

The court's decision is expected to increase pressure on the weak civilian government and beleaguered President Asif Ali Zardari, who has been linked to the memo that was delivered to former US military chief Admiral Mike Mullen by Pakistani-American businessman Mansoor Ijaz.