A special investigation committee accused some members of the National Democratic Party (NDP) of planning an attack on Tahrir protesters last month in what was branded as "the battle of the camel", a day that ended with intense violence and many casualties.
Dozens of thugs and camel and horse riders stormed Tahrir Square on 2 February in an apparent attempt to force the demonstrators out, following an emotional speech by former Egyptian President Hosni Mubarak who eventually stepped down on 11 February.
The incident sparked outrage in the country.
In its last report, which was submitted to the public prosecutor, the investigation committee, set up by the Supreme Council of the Armed Forces, said some NDP leaders, former parliament members and police officers incited thugs to attack protesters using bladed weapons.
Egyptian authorities on Saturday arrested former parliament member Abdelnasser El-Gabr, also a member of the NDP, on suspicion of orchestrating the attack. Several others are expected to be arrested during the coming few days, the committee said.
There had been widespread calls to dissolve the NDP, which ruled Egypt for more than 30 years.