Egypt's prosecutor general office has launched an investigation into what it describes as "fabricated" recordings by the Muslim Brotherhood of senior officials discussing ways to forge evidence against former president Mohamed Morsi.
The leaked recordings aired on pro-Morsi satellite channels on Friday, depicting a debate among senior military and security officials over forging trial evidence against Morsi before he was formally charged with multiple crimes under the civilian court system.
It allegedly features General Mamdouh Shahin, legal adviser to then army chief and now President Abdel Fattah al-Sisi, warning other senior officials in Sisi's office that the case against Morsi would collapse if documents were not forged.
Al Jazeera cannot independently verify the contents of the recordings.
The prosecutor general's office blamed the Muslim Brotherhood for fabricating the footage and telephone conversations "using advanced technology" with the aim of "causing disruption and destabilising society.''
In a statement, it vowed to fight such "crimes" and ordered an "extensive investigation to find those responsible."
Morsi has been in jail since he was overthrown last July and is on trial for inciting the killing of opposition protesters in December 2012 outside the presidential palace.
The deposed president also faces charges of espionage in collaboration with the Palestinian movement Hamas.
The Egyptian government has repeatedly said Morsi's toppling was not a "coup", but a decision taken after mass street protests rocked Cairo and other cities on June 30, 2013.
At least 1,400 people are estimated to have been killed, more than 15,000 jailed and hundreds sentenced to death since since authorities launched a brutal crackdown against Morsi supporters.