Defence lawyers in one of the Muslim Brotherhood's trials on Thursday denounced the absence of a key witness, whose written testimony was read out loud by the prosecution, according to judicial sources.

The defence team for the four defendants – including Brotherhood leader Mohamed El-Beltagi and Islamist preacher Safwat Hegazi – protested that the witness, who the prosecution said had travelled to Kuwait, did not attend the hearing. They asked for more details about his whereabouts, arguing that the witness's physical presence and testimony was essential to the case.

The judge ignored their pleas and continued with the proceedings.

The four defendants stand trial on charges of torturing two policemen at the main protest camp for ousted Islamist president Mohamed Morsi in front of Rabaa Al-Adaweya Mosque in east Cairo.

The sit-in was forcefully disbanded by security forces in August, killing hundreds.

The trial was adjourned to Saturday, as the judge gave the prosecution time to confirm the location of the witness.

Defence lawyers in ongoing trials for Brotherhood leaders and members have regularly complained of the judges being biased and have more than once asked to change the court.

Hundreds of Brotherhood defendants face trials on a variety of charges, some of which could lead to death penalty.