Prosecutor Andrew Edis QC read jurors a statement from Detective Inspector Martin Passmore explaining why certain people had not been called as witnesses in the case.
"Ms Briscoe has provided statements to the police in this case but during the investigation it became apparent that she may have lied about her involvement with the press and that she denied having any contact with the Mail on Sunday or any other media organisation in relation to this story," his statement said.
"Ms Pryce has not been arrested or interviewed in relation to that allegation.
"For this reason Ms Briscoe has been arrested and is currently under investigation by the police. Ms Briscoe could therefore no longer be relied upon as a witness of truth and on October 2, 2012 the Crown Prosecution Service took the decision not to call Ms Briscoe to give evidence in the case."