London, Aug 23 (IANS): British police have launched a probe into Edward Snowden's leak of classified US documents to the Guardian newspaper, noting the recently seized material was "highly sensitive", a government lawyer said Thursday.

"That which has been inspected contains, in the view of the police, highly sensitive material disclosure of which would be gravely injurious to public safety and thus, the police have now initiated a criminal investigation," Jonathan Laidlaw, a lawyer appearing for Scotland Yard, said Thursday.

Laidlaw made the announcement at the London High Court, where David Miranda, the Brazilian partner of Guardian reporter Glenn Greenwald, who helped Snowden disclose the classified material, sued Scotland Yard and the British home office to stop the police from carrying out further examination of the data seized from him, Xinhua reported.

According to the court ruling, the British police could examine the documents on condition that it was for the defence of national security and to investigate any possible links to terrorism.

Meanwhile, the home office and Scotland Yard, in order to continue with their investigation into the Snowden-linked material, would be needed to provide more evidence of the threat posed by the material at another hearing next Friday.

Miranda was held for nine hours without charge at Heathrow airport Sunday. His laptop, cellphone, memory cards and some DVDs were confiscated by British agents. He returned to Rio de Janeiro Monday.