Europe’s top justice official has expressed worries about press freedom in the UK after British authorities’ crackdown on the daily Guardian over its revelations of US spying programs based on leaks by Edward Snowden.

“I fully share [Council of Europe Secretary General Thorbjorn] Jagland’s concerns [over the issue],” said Viviane Reding, the EU’s commissioner in charge of privacy rules, in a tweeted message.

Jagland had called on British Home Secretary Theresa May to explain the pressure put on the newspaper by the British officials over Snowden case.

British Prime Minister David Cameron ordered his top civil servant Sir Jeremy Heywood to collect sensitive material which has been leaked to the paper by Snowden to be published.

Brazilian David Miranda, the partner of the Guardian journalist Glenn Greenwald, was also detained on Sunday at Heathrow Airport, where he was in transit on his way from Berlin to Rio de Janeiro.

Greenwald reported secret US National Security Agency’s surveillance programs revealed by Snowden, a former National Security Agency (NSA) contractor, in June.