No 10 'knew of Miranda Heathrow detention'
20 August 2013 Last updated at 22:43 BST
No 10 was "kept abreast" of the decision to detain David Miranda, the partner of the Guardian journalist Glenn Greenwald, a spokesman has said.
Mr Miranda was held at Heathrow for nine hours on Sunday, while in transit from Germany to Brazil.
He has launched a legal challenge over the police's use of anti-terror laws to detain him and seize his property.
Gordon Corera reports.