KHARTOUM: The judge presiding over the trial of ousted Sudanese president Omar al-Bashir over the 1989 coup that brought him to power stepped down on Tuesday citing health issues.

"I decided to cease presiding over the court for health reasons. I suffer from high blood pressure and my doctor advised me not to continue with this task," judge Essam Mohammed Ibrahim told the court.

The trial, which is broadcast on Sudanese television, was adjourned until January 5.

Proceedings opened on July 21 but have been repeatedly delayed.

Bashir is being tried with 27 others over the Islamist-backed coup in which he emerged as frontman.

He went on to rule Sudan for 30 years until his overthrow by the army in a palace coup in April last year, following unprecedented mass protests.

It is the first time in modern Arab history that the leader of a coup has been put on trial.

If convicted, Bashir and his co-accused -- including former top officials -- could face the death penalty.

Bashir has also been indicted by the International Criminal Court (ICC) over the deadly conflict in the Darfur region of western Sudan that broke out in 2003.

ICC prosecutor Fatou Bensouda met with Sudanese officials in October to explore options for trying Bashir over genocide, war crimes and crimes against humanity in Darfur.