The hearing into allegations of treason and hijacking against deposed Pakistani premier Nawaz Sharif has been adjourned again while defence lawyers await more evidence.

The judge in the case had been expected to decide on Tuesday whether formal charges could be laid, allowing the trial to start formally.

The military authorities say Mr Sharif jeopardised the lives of General Pervez Musharraf, now Pakistan' military ruler, and nearly 200 other passengers, when their plane was prevented from landing at Karachi airport on the night of the coup last October.

However, Mr Sharif's lawyers say the prosecution are withholding key evidence - tapes of conversations in the Karachi airport control tower on the day the army seized power.

The prosecution is supposed to provide the defence with copies of the material.

Tape copying

A prosecution lawyer said during Tuesday's session that copying the tapes would take time, and that the laying of formal charges did not have wait until all the evidence was handed over. The charges are expected to include attempted murder, attempted hijacking and waging war against Pakistan.

However, defence lawyers argued for a further delay because the evidence was so important.

Mr Sharif insists the case against him is fabricated and, in comments to reporters attending his hearings, he has become increasingly critical of General Musharraf's performance.

Judge changes

A new judge was put in charge last week after proceedings were interrupted because of the presence of plain clothes intelligence officials in the courtroom.

The military had hoped for a rapid trial. But the process has been marked by a series of delays - many resulting from technical legal arguments about who has jurisdiction over the case and the nature of the evidence which the prosecution should be allowed to use.