Bangladesh's highest court has halted the execution of a top opposition leader, just an hour and a half before he was set to become the first person executed for war crimes committed during the country's 1971 war of independence.

Abdul Qader Mollah, a leader of the Jamaat-e-Islami political party, was due to be hanged at 18:00GMT on Tuesday, his lawyer said. His original life sentence had been overturned by the Supreme Court in September, after mass protests called for him to be hanged.

"The chamber judge of the Supreme Court has stayed the hanging until 10.30am [04:30GMT on Wednesday]," Mollah's defence lawyer Shishir Munir told the AFP news agency.

Earlier, Quamrul Islam, the country's deputy law minister, confirmed that authorities intended to hang Mollah on Tuesday night, and that he had refused the option of seeking a presidential pardon.

Prisons chief Main Uddin Khandaker said all preparations had been made to carry out the execution, and Mollah's family had been asked to meet the 65-year-old senior leader of the Jamaat-e-Islami party for the last time.

On Sunday, a tribunal signed an execution order for Mollah, and sent it to the main jail in the capital Dhaka, raising speculation that the former journalist could be hanged any moment.

Violence feared

US-based activist group Human Rights Watch and a UN Special Rapporteur on the independence of judges and lawyers have warned that by executing Mollah without giving him the opportunity to appeal for a review, the country could be breaking international law.

There are also worries the execution could trigger more violence, with the country already reeling from its worst political unrest since independence ahead of a national election on January 5.

At least 224 people have died in battles between opposition protesters, police and government supporters since January this year.

"What logic do they have to stop the execution?" minister Islam told AFP when asked about the criticism from rights experts.

"Did they stop the execution of Saddam Hussein?" he said referring to the former Iraqi leader who was hanged in December 2006.

Mollah was convicted of rape, murder and mass murder including the killing of over 350 unarmed Bengali civilians. Prosecutors described him as the "Butcher of Mirpur", a Dhaka suburb where he committed most of the atrocities.

A domestic war crime court had originally sentenced him to life imprisonment in February, but the sentence prompted protests by tens of thousands of secular demonstrators who viewed it as too lenient.

Under pressure, the government amended the war crime law retroactively to allow it to appeal the sentence and seek the death penalty, which the Supreme Court then handed down in September.