Footage from video cameras in Westgate is not always recorded, a manager at the prison told Supreme Court yesterday.

Ferdinand Thorne said there were two cameras in the unit where Kenneth Burgess and Kamel Trott are accused of attacking Dennis Robinson during a recreation break on June 6 last year.

But Mr. Thorne, who is in charge of Westgate's CCTV system, told the jury: "If the digital video recorders are in playback mode, they do not record."

He was one of a number of prison officers to give evidence in a day of mainly technical discussion on prison operating procedures yesterday.

The case has previously heard how camera footage disappeared after the alleged incident, in which Mr. Robinson says he was ambushed in his cell, suffering serious facial injuries in a vicious punching attack lasting an hour.

Last week, Richard Horseman, representing Robinson, had asked prison officer Gladwin Simons: "Are you aware that an attempt was made to bring back the videotape of June 6, but the footage was missing for that particular day?"

Mr. Simons had replied that he was aware of the attempt, but not that the footage was missing.

Robinson has previously told the jury that Burgess blamed him for his incarceration and threatened to kill him, before instructing him to write an affidavit clearing him of blame in the Cooper twins case.

Burgess, 36, and Trott, 32, deny assault with intent to do grievous bodily harm.

The trial continues.