In 2015, a court sentenced Morsi to death over the case but Egypt's top appeals court overturned the verdict and ordered a retrial
Egypt's deposed president Hosni Mubarak on Wednesday asked current President Abdel Fattah al-Sisi for "permission" to disclose sensitive information in the retrial of ousted Islamist leader Mohamed Morsi.
Toppled in 2011 after mass protests against his nearly 30-year-rule, Mubarak took the witness stand in a Cairo court to testify about jailbreaks allegedly orchestrated by Morsi and other members of his Muslim Brotherhood group during the uprising.
Prosecutors say they were sprung from prison with the help of the Palestinian group Hamas and operatives from Lebanon's Hezbollah movement.
In sworn testimony, Mubarak declined to answer all of the judge's questions until the presidency granted him "permission" to reveal "sensitive" information related to national security.
"If I talk, I will open many subjects that I am barred from discussing without permission," he said.
The former president acknowledged that at the time, he had received information from his intelligence chief on the infiltration of militants from the Gaza Strip to the country's east during the uprising.
"General Omar Suleiman informed me on January 29 (2011) that 800 armed militants infiltrated through the border," he said, adding that militants from Hamas group, assisted by North Sinai residents, used underground tunnels to cross.
The judge also asked Mubarak questions about the involvement of Hezbollah operatives.
On the border with Gaza, North Sinai is the epicentre of an Islamist insurgency that erupted following Morsi's military ouster in 2013.
Egypt in recent years has built a buffer zone along the border to stem the flow of militants.
Mubarak said the militants had attacked police stations, killed security personnel and helped spring Morsi and other senior Brotherhood members from detention.
In 2015, a court sentenced Morsi to death over the case but Egypt's top appeals court overturned the verdict and ordered a retrial.
Morsi ruled Egypt for just a year before mass protests spurred then army chief and now President Sisi to overthrow him in July 2013.