The Sunday Times received a judge's permission yesterday to challenge the legality of a recent police raid on its offices in Belfast.
In the High Court in Belfast, Mr Justice Kerr granted leave to apply for a judicial review.
Barrister Brett Lockhart argued that the raid was illegal because the search warrant was deficient.
He said that, under legislation, a warrant to search for journalistic material required the signature of a judge.
But the warrant used by police had only been signed by a Justice of the Peace.
The raid followed disclosures by the paper's Northern Ireland editor Liam Clarke concerning bugged telephone conversations between Sinn Féin's Martin McGuinness and former secretary of state Mo Mowlam.
Mr Clarke's home at Ballymena was also raided. His solicitor, Paul Tweed, said he had now been instructed to issue separate legal proceedings.
