Scotland Yard pursuing a criminal investigation following intelligence leaks to the Guardian

A senior British police official says her force is pursuing a criminal investigation following the leak of classified material on U.K. and American intelligence-gathering techniques to the Guardian newspaper.

In a letter sent last month to British lawmaker Julian Smith, Metropolitan Police Assistant Commissioner Cressida Dick says she had a team of detectives working on the leak inquiry.

The letter, dated Oct. 24, did not go into any further detail or say whom such an inquiry might target.

Scotland Yard said Tuesday that the investigation was announced last month, although it appears to have attracted virtually no attention at the time.

The Guardian did not immediately return messages seeking comment.