The BBC has apologized for revealing details of a conversation with Queen Elizabeth II in which the monarch allegedly voiced concerns about the U.K.'s inability to arrest a radical cleric, Abu Hamza al-Masri.

Considered Britain's most recognizable extremist, al-Masri is wanted in the U.S. for a raft of alleged terrorist offenses. A European court decision Monday cleared the way for his extradition and that of four other terror suspects after an eight-year legal battle. He could now be deported within weeks.

On Tuesday, BBC journalist Frank Gardner recounted that in conversation years ago, the queen said she had mentioned she was upset that al-Masri had not been arrested.

The BBC later apologized for the breach of confidence in revealing the details of a private conversation.