The Court of Cassation ruling, which is final, overthrew a 15-year sentence for Morsi on charges of stealing the documents, handed during the initial sentencing.
Cairo Criminal Court sentenced Saturday seven members of what is known in the media as the "Libya terrorist cell" to death on a number of terror-related charges.
A referral to the mufti is required in the Egyptian court system ahead of death sentences, even though the mufti's opinion is advisory not binding.
In October last year, the same court had confirmed a 20- year prison sentence against Morsi for taking part inciting violence near Ittihadeya presidential palace in 2012.
South Africa batsman JP Duminy announces retirement from Test cricket
Duminy's illustrious nine-year Test career ends with tally of 2,103 runs at 32.85 off 46 matches. His last Test was the series opener against England at Lord's earlier this year.
He came to power after Egypt's long-time president Hosni Mubarak was toppled in an uprising in 2011.
Prosecution referred the defendants to trial court a year ago for forming a terrorist cell affiliated to the "Islamic State (IS)" faction in Libya, alleging that a number of the defendants were involved in the beheading of 21 Egyptian Coptic Christians.
In November 2016, the case was referred to court, after the State Security Prosecution revealed the defendants were also involved in attacks on Christians in their governorate, as well as hiding and training seven German citizens who were planning to join Libya's Daesh. However, the verdict can be appealed.
The defendants are also charged with participating in the beheading of 21 Egyptians in Libya.