Sadat was the first Arab leader to recognise Israel since its creation in 1948

Tarek al-Zomor has served out a 22-year jail term for conspiracy and membership of the outlawed Egyptian Islamic Jihad group, the court said.

The interior ministry had been continuing to hold him on the grounds that he is a risk to national security.

Four soldiers were executed for the attack on President Sadat, during a military parade in 1981.

There are no reports that al-Zomor has actually been released.

The news agency AFP reported that the interior ministry had launched an appeal to a higher court.

The ministry is allowed to detain inmates for five years beyond their sentence if they are deemed a security risk.

Cousin held

But the administrative court at the Council of State reportedly ruled his continued detention was "a violation of his personal right to freedom and to return to his family".

The court denied a similar request for release from al-Zomor's cousin, AP news agency reported.

Lt Col Abboud al-Zomor has also served 22 years for his role in planning Sadat's murder.

The agency said it was unclear why Col al-Zomor's request had been turned down.

"This is a violation of the prisoner's legal rights," it quoted the attorney for the two prisoners, Nizar Ghorab, as saying.

Radical clash

Anwar Sadat was shot on 6 October 1981 by Khaled al-Islambuli, also a member of the Egyptian group Islamic Jihad, during a military parade.

Islamic radicals had condemned Sadat for being the first leader in the Arab world to sign a peace treaty with Israel, in 1979.

He had initially sought the backing of Islamists in a political struggle against left-wingers, but growing radicalism turned them against the president.

Sadat was succeeded by Hosni Mubarak, who remains president to this day.