A Brazilian man held at Heathrow airport under anti-terror laws today launches a High Court challenge over the legality of his detention.

David Miranda is the 28-year-old partner of a Guardian journalist who exposed secret information on US surveillance leaked by whistle-blower Edward Snowden.

Mr Miranda was held for nine hours and questioned under Schedule 7 of the Terrorism Act 2000 on August 18, a Sunday.

His lawyers are arguing his detention for the maximum period allowed was a misuse of Schedule 7 and breached his human rights.

Mr Miranda had nine items, including his laptop, mobile phone, memory cards and DVDs, taken from him while detained.

He was stopped while changing planes on a journey from Berlin to Rio de Janeiro where he lives with journalist Glenn Greenwald.

High Court judges have already ruled that the material seized from him could only be examined for national security purposes and the protection of the public, and no other.

Mr Snowden, a former contractor with the US National Security Agency, has been granted temporary asylum in Russia.