Mohammad Rabbani
© PHOTOSHOT/AVALON.REDMohammad Rabbani
Muhammad Rabbani was held at Heathrow after returning from the Gulf where he was investigating a torture case allegedly involving the US

The international director of Cage, Muhammad Rabbani, has been charged under the Terrorism Act after refusing to hand over passwords to his laptop at Heathrow airport.

Rabbani, who regards it as a privacy v surveillance test case, said he intended to fight the charge. "I am innocent of these charges that have serious implications for journalists, lawyers and human rights," he said.

He is due to appear at Westminster magistrates court on 20 June.

Rabbani, 35, from London, is involved through Cage in investigating torture cases. He said he was stopped at Heathrow in November returning from one of the Gulf states where he had been investigating a torture case allegedly involving the US.

He said he handed over his laptop and mobile phone but refused to provide his passwords. Although not a lawyer, he said the laptop contained information about the case and the client refused permission to release it. Rabbani was then arrested.

A spokesman for Cage said Rabbani was charged with wilfully obstructing or seeking to frustrate a search examination under schedule 7 of the Terrorism Act, which gives border officials sweeping search powers.

The case comes against the backdrop of a similar campaign in the US against proposals by the Trump administration to make entry by non-Americans conditional on handing over passwords.

In an earlier interview with the Guardian, Rabbani said he had been detained 20 times over the last decade by border officials and had handed over his laptop and mobile phone. On previous occasions, after refusing to hand over passwords, they were returned to him and he was allowed to go. But not on this occasion.

In 2013, the partner of journalist Glenn Greenwald, David Miranda, was stopped at Heathrow under the same legislation in the wake of the Edward Snowden case. Miranda launched a successful legal challenge.