Police held David Miranda, the 28-year-old partner of Guardian journalist Glenn Greenwald, under anti-terror laws.
Greenwald has recently worked on high-profile articles about US surveillance programs.
Miranda had been en route from Berlin, Germany, to Rio de Janeiro, Brazil, where the couple live, when he was detained in London for nine hours.
Police said they held Miranda under terrorism powers before he was allowed to continue on his journey to Brazil.
Asked to confirm whether a camera was among items confiscated, a Metropolitan Police spokesman told Amateur Photographer: ‘We are not getting involved in saying what items may or may not have been taken.’
Miranda has today taken legal action over police use of anti-terror powers, according to reports.
Last night, the Metropolitan Police defended its use of Schedule 7 of the Terrorism Act 2000, saying that its examination of Miranda was ‘both necessary and proportionate’ and that its use of the power was ‘legally and procedurally sound’.
The Act, which deals with port and border controls, states that an officer may ‘examine goods… for the purpose of determining whether they have been used in the commission, preparation or instigation of acts of terrorism’.