An Egyptian court sentenced Muslim Brotherhood leader Mohamed Badie and 682 other alleged Islamists to death on Monday, a lawyer and prosecutor said, after two brief sessions the defense partly boycotted.

The same court in the southern province of Minya also reversed 492 of 529 death sentences it passed in March, commuting most of those to life in prison.

The court, presided over by judge Said Youssef Sabry, had sparked an international outcry with its initial sentencing last month amid an extensive crackdown on supporters of ousted Islamist president Mohammed Morsi.

Under Egyptian law, death sentences are referred to the top Islamic scholar for an advisory opinion before being ratified. A court may choose to commute the sentences, which can later be challenged at an appeals court.

The judge will confirm the verdict on June 21.

'Farcical' trial

Of the 683 people sentenced on Monday, only about 50 are in custody. The others have a right to a retrial if they hand themselves in.

Monday's hearing lasted just 10 minutes, said Khaled Elkomy, a defense lawyer who was in court.

The verdict was the first against Badie, spiritual head of Morsi's Muslim Brotherhood, in the several trials he faces on various charges along with Morsi himself and other Brotherhood leaders.

Those sentenced on Monday were accused of involvement in the murder and attempted murder of policemen in Minya province on Aug 14, the day police killed hundreds of Morsi's supporters during clashes in Cairo.

Defense lawyers boycotted the last session, branding it "farcical" after the mass death sentencing, which the United Nations denounced as a breach of international human rights law.

Lawyer Elkomy claims that 60 percent of the 529 defendants, including teachers and some doctors, have evidence that "proves they were not present the day they were accused of attacking the Matay police station" in Minya, a statement by human rights group Avaaz said.

The government has defended the court's handling of the first mass death sentences, insisting that the sentences were passed only "after careful study" and were subject to appeal.

Prosecutor Abdel Rahim Abdel Malek defended the charges against the 529.

"We have strong evidence that incriminates all those sentenced to death," he said.