Alexandria Security Chief Nasser El-Abd told state TV that the helicopter which was to transfer ousted president Mohamed Morsi to New Cairo for the second session of his trial on charges of inciting murder could not take off from his Alexandria prison due to bad weather conditions.
The trial was set to start at 10:30am Cairo Local Time.
It remains unclear whether the ousted president will attend Wednesday's session.
Earlier on Wednesday morning, Al-Ahram's Arabic news website had reported that a helicopter flew the toppled leader from his heavily-guarded prison in the Mediterranean city of Alexandria to the courtroom in the Police Academy on the eastern outskirts of Cairo.
Morsi's doubtful appearance on Wednesday would be his second public sighting since the army deposed him last July after millions protested his troubled year-long rule. His first appearance took place during the first session of the trial on 4 November.
Morsi, along with 14 co-defendants, including Muslim Brotherhood leaders and former presidential advisors, is accused of inciting the murder of opposition protesters in clashes outside the Presidential Palace in December 2012.
If convicted, Morsi -- Egypt's first freely elected president -- could face the death penalty.
An Islamist grouping led by the Brotherhood had called on Sunday for mass rallies to coincide with the Wednesday morning hearing.
Morsi will also stand trial on 28 January over a jailbreak during the 2011 popular uprising that toppled long-time autocrat Hosni Mubarak.
He will also face a separate trial on charges of espionage. A date for the trial has yet to be set.