Detectives have been granted more time to question four people arrested this month over a suspected terror plot in the UK, police said Thursday. Officers from Scotland Yard's counter terrorism command now have until this Monday to question the suspects, including British Muslim convert Richard Dart. The three others being held are a 21-year-old man who was detained in Ealing, west London, a 26-year-old man arrested in Newham and a 22-year-old woman detained in Hackney, both in east London and close to the Olympic site in Stratford. The warrants for further detention were granted at Westminster Magistrates' Court yesterday, police said. Dart, 29, who changed his name to Salahuddin al-Britani after converting, appeared in a BBC TV Three documentary, "My Brother The Islamist", made by his stepbrother Robb Leech last year, which described how Dart, originally from Weymouth, Dorset, southern England, had been converted by controversial cleric Anjem Choudary. In the documentary he spoke of his support for jihad and sharia law. Seven people have been arrested in connection with the alleged plot but three have been released, including two men detained in Newham, who were released yesterday. A 30-year-old woman who was arrested in Ealing was released last Saturday. One of the men arrested served as an aide with the Met between May 2007 and September 2009, when he resigned. He was not deployed in a specialist or sensitive role, Scotland Yard said. The alleged plan involved Islamist extremists with potential targets in the UK, but was not linked to the Olympics, it is revealed by police sources in leaked reports to the media here. The threat to the UK from international terrorism is currently rated substantial - the third highest of five levels.