In a related development, Egypt's attorney-general vowed on Wednesday to bring to justice officials responsible for the theatre blaze.
Legal chief Maher Abd al-Wahid said on Wednesday "nobody is above the law".
The deaths occurred after fire was apparently set off by lighted candles used during a performance on 5 September at a theatre in Beni Suef, south of Cairo.
The fire triggered a deadly stampede as the audience tried to flee.
Abd al-Wahid said eight people had been detained in connection with the inferno, the deadliest Egypt has witnessed in years.
Judicial sources said they face charges of negligence and accidental murder.
Abd al-Wahid's comments come just days after some 150 Egyptian artists and writers filed a suit against the ministers of culture, interior and health, accusing them of dereliction of duty.
"The investigations will cover all - big and small - and those found responsible will be brought to account," the attorney-general promised.
Dozens of people in the audience
suffered serious burn injuries
Safety regulations in public places are rarely enforced in Egypt and television footage showed a man using a tiny fire extinguisher to battle the flames.
The performance of the play Zoo was part of an experimental theatre festival that brought together actors from across Egypt.
Interior Ministry sources said the dead included three actors, three students from an arts academy and three journalists.