The BBC says it regrets revealing the Queen once personally raised concerns with the government about why Abu Hamza hadn't been arrested.

The Corporation's sent a letter of apology to Buckingham Palace, after Security Correspondent Frank Gardner earlier reported details of a private conservation he'd had with Her Majesty about the radical Muslim cleric.

Hamza's expected to be extradited from Britain to the United States soon ... after the European Court of Human Rights rejected his final appeal.