A police officer and two journalists were arrested on Wednesday as part of an operation related to the phone-hacking controversy at media baron Rupert Murdoch's now-defunct 'News of the World'.
The arrests were made under 'Operation Elveden', which is investigating allegations of inappropriate payments to police and public officials by news organisations.
It is running along with 'Operation Weeting' into phone-hacking of voicemail boxes.
Scotland Yard said that the policeman, 39, who is a serving officer of the Wiltshire police, was arrested at his home in Wiltshire on suspicion of misconduct and to commit misconduct in a public office.
The two journalists arrested were described by the police as a 51-year-old man from Bristol and a 32-year-old man from south-east London.
Both were arrested on suspicion of conspiracy to corrupt and conspiracy to cause misconduct in a public office.
The Yard said: "Today's arrests are the result of information provided to police by News Corporation's Management Standards Committee. They relate to suspected payments to a public official and suspected disclosure of confidential information by a police officer and are not about seeking journalists to reveal confidential sources in relation to information that has been obtained legitimately."