The Guardian newspaper has gone to Britain's High Court to demand an injunction protecting materials that were seized from the partner of a journalist who has written stories based on documents leaked by former National Security Agency contractor Edward Snowden.

Lawyers for David Miranda, the partner of Guardian reporter Glenn Greenwald, say the seized material contains confidential information. British officials took computers, memory sticks and other electronic items from Miranda when he was questioned at Heathrow Airport under Schedule 7 of the Terrorism Act.

Lawyer Gwendolen Morgan said Thursday that sources and confidentiality must be protected.

Greenwald has written about NSA programs using files disclosed by Snowden, who now has temporary asylum in Russia. The Obama administration wants Snowden to face trial in the United States for the leaks.