CAIRO, Egypt -- The family of Egypt's ousted president will not attend his trial, his son said Sunday, a day before it opens in Cairo amid heightened security and planned Muslim Brotherhood protests that could again deteriorate into deadly street violence.

Osama Morsi told The Associated Press that Mohammed Morsi's family does not recognize the trial's "legitimacy," and consider him "kidnapped," and held as a "hostage."

The remarks come as U.S. Secretary of State John Kerry was in Cairo pressing for reforms during the highest-level American visit to Egypt since Morsi's ouster. The coup and the ensuing crackdown on his protesting supporters led the U.S. to suspend hundreds of millions of dollars in aid.

Morsi has been under arrest since the July 3 military coup, which followed protests by millions calling for him to leave office. He is held in an undisclosed location, virtually incommunicado except for a few phone calls to his family.

Morsi is scheduled to face charges of inciting violence and murder in connection to clashes in front of presidential palace in December.

In recent statements, a coalition led by Morsi's Brotherhood described the trial as a "farce" and reiterated that it regarded him as the "elected, legitimate president" of Egypt. "This is a naive tool to break our will and our determination," it said Sunday.

The prospects of a new confrontation between security forces and Morsi supporters on the trial day are high. A Brotherhood-led group has called for mass rallies, while the interior minister has ordered the deployment of large number of security forces to guard the trial venue, a police institute in southern Cairo.

It is unclear whether the trial will be aired live or if Morsi will return to his current place of detention or join fellow Brotherhood leaders who are detained in Torah prison, adjacent to the trial venue.

International rights groups urged interim authorities to both investigate previous killings and to ensure a fair trial.

In a Sunday statement, London-based Amnesty International said Morsi's trial is a "test" for the Egyptian authorities, who must grant him the "right to challenge the evidence against him in court," said Hassiba Hadj Sahraoui, Amnesty's Middle East director. "Failing to do so would further call into question the motives behind his trial."

The group called for either releasing Morsi or transferring him from his secret place of detention to a known facility.

Morsi is being tried along with 14 other Brotherhood members and allies including top leaders Mohammed el-Beltagi and Essam el-Erian as well as three of Morsi's top aides, Ahmed Abdel-Atti, Assad Shaikha, and Ayman Houdhoud. Two young Islamist activists -- Ahmed el-Mougheer and Abdel-Rahman Ezz -- as well as ultraconservative Salafi Gamal Saber and hard-line preacher Abdullah Badr are also among the defendants.

The incident goes back to Dec. 5 when thousands of Egyptians led by democracy advocates amassed in front of the presidential palace, demanding Morsi to cancel an autocratic constitutional declaration which temporarily put him above the courts.

When policemen appeared reluctant to disperse the crowd, supporters of the president attacked protesters, sparking clashes that left 10 dead. Prosecutors say Morsi and the Brotherhood were behind the attacks, which saw many badly beaten and some even tortured inside the presidential palace.

Among those killed was a young journalist and activist, el-Husseini Abu-Deif, who became another icon for democracy advocates.

Thousands of the Brotherhood's members, supporters and allies have been detained since Morsi's overthrow in July. Many have been referred to court in relation to protests and clashes that erupted before and after the army forced the Islamist Morsi from power.

Egypt witnessed one of its bloodiest days in decades on Aug. 14 when security forces violently cleared pro-Morsi protest camps, a move that sparked days of unrest as well as attacks on churches and police. An alliance of groups led by the Brotherhood continues to hold demonstrations that frequently result in violence.