The Sun has insisted all its journalism on the Tulisa drugs sting was within the Press Complaints Commission code after complaints from the singer's lawyers yesterday after she was charged with dealing cocaine.
Tulisa Contostavlos, 25, was arrested on 4 June – two days after The Sun on Sunday reported on how she allegedly set up an £800 drug deal with a reporter.
Lawyers for the singer said yesterday complained that her arrest only came about as a result of the actions of The Sun on Sunday and its undercover investigative journalist Mazher Mahmood.
A spokesperson for The Sun said: "The Sun on Sunday's investigation into Tulisa Constovlos was entirely justified in the public interest.
"It was undertaken by Mazher Mahmood, or award-winning journalist responsible for the football match-fixing investigation that has dominated the news recently.
"Ms Constovlos is a self-described role model for young people and therefore as certain responsibilities. Throughout our investigation, our team followed the Press Complaints Commission code and then handed our dossier of evidence to the police.
"Following the police investigation, prosecutors have decided there is a clear case to answer.
"It is right that this matter should go to court and be decided by a jury.
"Allegations about the conduct of this newspaper made by Ms Contostavlos' lawyers are entirely without foundation."
CPS London chief crown prosecutor Baljit Ubhey said: "The Crown Prosecution Service has today authorised the Metropolitan Police Service to charge Tulisa Contostavlos, 25, with being concerned in the supply of Class A drugs.
“This charge relates to an investigation by The Sun newspaper between early March 2013 and 23 May 2013 which resulted in the supply of Class A drugs to an investigative journalist.
"This decision to prosecute was taken in accordance with the Code for Crown Prosecutors. We have determined that there is sufficient evidence for a realistic prospect of conviction and that a prosecution is in the public interest.
"Ms Contostavlos will appear before Westminster Magistrates' Court on 19 December 2013.
"This defendant is now the subject of criminal proceedings and has the right to a fair trial. It is extremely important that nothing should be reported which could in any way prejudice these proceedings."