One of four people accused along with former Pakistani Prime Minister Nawaz Sharif has agreed to testify against him in a case involving possible hijacking and kidnapping charges, a prosecutor said Wednesday.

Sharif, who was ousted in a bloodless military coup on October 12, has been remanded in custody with the other accused until Friday, when formal charges may be laid.

Raja Qureshi, one of the three prosecutors in the case, said former Civil Aviation Authority chief Aminullah Chaudhry had volunteered to testify against Sharif in the case, which could lead to a death penalty, and had asked for a pardon.

``He applied for a pardon under the code of Criminal Proceedings on his own request,'' said Qureshi, who is also the advocate-general of Sindh province.

``It has been granted by the competent authority and his statement has been recorded. He enjoys the status of an approver in the trial,'' Qureshi told Reuters.

In Pakistan, an approver is an accomplice in a crime who decides to give evidence against another prisoner.

``His statement has been recorded yesterday and will be presented in a trial court,'' Qureshi added.

Sharif's lawyer dismissed the news when speaking to reporters after Sharif made an appearance before a judicial magistrate to hear witnesses give statements against him, part of the legal process before the formal laying of charges.

``He had been compelled to become an approver, but I'm sure this will not have any impact on the case,'' said Khalid Anwar, a law minister in Sharif's government.

Sharif may also be charged with criminal conspiracy and attempted murder, but the hijacking accusation is the most serious because it can carry a death penalty.

The others accused are former Sharif adviser Ghous Ali Shah, former Pakistan International Airlines chairman Shahid Khakan Abbasi and former Sindh province police chief Rana Maqbool.

All three appeared with Sharif before the judicial magistrate, but Chaudhry did not.

Sharif has proclaimed his innocence and said his government's removal was illegal. He has called on the world to ensure he gets a fair trial.

The allegations stem from an alleged attempt to divert a plane bringing army chief General Pervez Musharraf to Karachi from Sri Lanka on October 12.

Hours later, Musharraf overthrew Sharif's government.

The former chairman of Pakistan's Civil Aviation Authority has broken with his co-defendants, including deposed Premier Nawaz Sharif, and has agreed to testify against them in their treason and hijacking trial, a party official said Wednesday.

Aminuddin Chaudhry is expected to explain who denied landing rights to a passenger aircraft returning Pakistan's army chief Gen. Pervez Musharraf to Karachi on Oct. 12.

The plane was eventually allowed to land -- with seven minutes of fuel to spare -- after army soldiers took over the Karachi Airport control tower.

Sayed Hafizuddin, an official from Sharif's Pakistan Muslim League, said Chaudhry agreed on Tuesday to testify against Sharif and the other co-defendants in the case.

Raja Quereshi, the attorney general for southern Sindh province, told The Associated Press that the former Civil Aviation Authority chairman has already given a statement to police.

The charges against Sharif and Chaudhry stem from actions on the day the army overthrew Sharif in a bloodless coup.

Sharif was deposed by Musharraf after the general's landing rights were denied.

Sharif has said he is innocent. During an earlier court appearance, he said the army has "hijacked the constitution and has hijacked democracy in Pakistan."

He arrived Wednesday in an armored personnel carrier at the Malir court building in Karachi to hear Nadeem Akbar, a civil aviation official, testify in the case.