The British government, accused of abusing media freedom, said on Tuesday police were right to detain a journalist's partner if they thought lives might be at risk from data he was carrying from fugitive U.S. intelligence contractor Edward Snowden.
Facing legal and diplomatic complaints after police held Guardian writer Glenn Greenwald's Brazilian partner for nine hours on Sunday - and accused by the newspaper of forcing it to trash computers holding copies of Snowden's data - the interior minister said officers were entitled to take security measures.
Home Secretary Theresa May said police held David Miranda at a London airport under anti-terrorism powers, which allow for action to prevent stolen data to aid terrorists. Material from Snowden, published by the Guardian, has revealed extensive U.S. and British surveillance of global communications networks.
"It's absolutely right that if the police believe that somebody is in possession of highly sensitive, stolen information that could help terrorists, that could risk lives, lead to a potential loss of life, the police are able to act - and that's what the law enables them to do," May told the BBC.
She added, however, that an independent reviewer was looking into the police conduct.
As interior minister, May said she was briefed in advance that Miranda might be stopped but added that she did not decide who the police detained. The United States said Britain gave it a "heads up" but it did not ask for Miranda to be questioned.
Snowden, who faces criminal charges in the United States, has been granted a year's asylum by Russia.
A British lawyer who launched an action on Miranda's behalf to question the legal basis of his detention said police seized a laptop computer, a telephone, memory sticks, a computer hard drive and a games console from him. He was released without charge after reaching a time limit on such detentions.
Miranda had been in transit at Heathrow airport, carrying material from Snowden that was being passed from Berlin-based American documentary filmmaker Laura Poitras to Greenwald, an American writer for Britain's Guardian who lives in Rio de Janeiro.
"These items contain sensitive, confidential journalistic material and should not