Businessman Hussein Salem, a close associated of Mubarak, is being retried in his absence - he went to Spain after being cleared of fraud in his first trial.

BBC: Egypt judge withdraws from Mubarak trial

Prosecutors said last month, in proceedings related by civil rights lawyer Khaled Abu Bakr, that Mubarak's businessman friend Hussein Salem got the right to export gas to Israel through a private company Salem owned.

CNN: Egyptian companies abruptly halt gas exports to Israel