Muslim Brotherhood Secretary-General Mahmoud Hussein is "just as shocked" as other people at the acquittal of 25 former regime officials for their role in the Battle of the Camel during Egypt's revolution, he said on Thursday.
He also backed Friday's protests against the verdict via a statement on the Freedom and Justice Party's (FJP) Facebook page.
The protest, which was originally called for by secular groups to demand the revolution's demands are achieved, will call for a retrial of the case, and some groups have said they want an independent committee to reinvestigate the case.
The Brotherhood will be protesting against the verdict, not in support of the secular groups' other demands.
On Wednesday, 25 defendants were acquitted of orchestrating the so-called Battle of the Camel on 2 February 2011 in Cairo's Tahrir Square.
Among those acquitted were former chairman of the Shura Council Safwat El-Sherif, former National Democratic Party MP Mohamed Abul-Enein, former parliamentary speaker Fathi Sorour, former labour minister Aisha Abdel-Hadi, and lawyer Mortada Mansour, who allegedly recorded a speech the night before the battle inciting thugs to attack protesters in Tahrir Square.
Friday's protest was first called for on Saturday by 21 secular groups demanding the fulfilment of the revolution's demands, among which they said were a constitution that reflects the diversity of Egyptian society.
Among the groups that called for the protest were the Constitution Party, April 6 Youth Movement (Democratic Front) and Hamdeen Sabbahi's Popular Current.