The appeal filed by lawyers for Abu Hamza al-Masri and four other suspects late on Monday will delay attempts to put the Egyptian-born cleric on trial on charges he supported al Qaeda and aided a fatal kidnapping in Yemen.

A panel of five judges could decide within a few weeks on the merit of the appeal, judicial sources said.

In April, the court ruled it lawful for Britain to extradite al-Masri, famed in the British media as a one-eyed radical with a metal hook for a hand, to the United States, where he could face a sentence of over 100 years in high security "Supermax" prisons.

That ruling similarly applied to Barbar Ahmad, Syed Tahla Ahsan, Adel Abdul Bary and Khaled Al-Fawwaz, all incarcerated in Britain, three of whom have been under indictment for years in New York.

Lawyers for al-Masri had argued that such treatment would contravene his human rights. The appeal focuses on the risk of being subjected to "inhuman and degrading treatment" in such prisons, the sources said.

If the appeal is deemed valid, it will be judged by the grand chamber of 17 judges at the Strasbourg-based court It is rare for a case to be accepted to be heard by that full body.

Al-Masri is viewed as one of the most radical Islamists in Britain where he was once a preacher at a North London mosque but was later jailed for inciting murder and racial hatred. He is being held in a British jail.

He was indicted in 2004 by a federal grand jury in New York, accused of providing material support to al Qaeda and for involvement in a 1998 hostage taking in Yemen in which four hostages were killed. (Reporting by Gilbert Reilhac; Writing by Alexandria Sage; Editing by Robin Pomeroy)