Mubarak, 85, was sentenced to life in prison last year for failing to stop the killing of protesters during the uprising against him in 2011. But the appeals court accepted his appeal in January and ordered a retrial.
He is now being retried on those charges, but has served the maximum amount of pre-trial detention permitted in the case.
The last remaining corruption case relates to allegations that Mubarak received gifts from a state-run publisher. However, his family has paid back the value of the alleged gifts, strengthening Deeb's confidence that he will be released.