A 48-year-old former Special Branch officer has been charged with offences under the British Official Secrets Act.
It follows an investigation into the alleged leaking of transcripts of phone calls between Sinn Féin's Mr Martin McGuinness and senior British government officials.
The former police officer who was arrested on Wednesday, was bailed yesterday to appear in court at a later date.
Earlier yesterday, the Northern Ireland editor of the Sunday Times, Mr Liam Clarke and his wife Ms Kathryn Johnston were released on bail pending further inquiries.
The pair, who co-wrote a biography of Mr McGuinness, entitled From Guns to Government, were also questioned about the transcripts which were said to detail conversations between Mr McGuinness and former Northern Ireland Secretary Ms Mo Mowlam as well as Mr Tony Blair's chief of staff Mr Jonathan Powell.