According to a Metropolitan Police statement, the information relates to activity at the News of the World in 2005/2006.
Shortly after the Met police's announcement, the News of the World confirmed that its assistant editor (news), Ian Edmondson, who was suspended earlier this month pending an internal investigation, has been sacked.
In a statement today, a spokesman from the newspaper said: "The News of the World has terminated the employment of Ian Edmondson, assistant editor (news).
"Mr Edmondson was suspended in December 2010 following a serious allegation. Material evidence found during the course of the subsequent investigation has led to Mr Edmondson's dismissal.
"News International has informed the police, handed over the material it has found and will give its full co-operation going forward.
"News International reiterates that it will take swift and decisive action when we have proof of wrongdoing."
The re-opening of the investigation follows a statement earlier this week from the director of public prosecutions, Kier Starmer QC, claiming that the Crown Prosecution Service would take a "robust approach" to "any recent or new substantive allegations" made to the Met police.
Earlier this month, the CPS announced that it will conduct a "comprehensive assessment" of evidence held by the Met police in relation to the case.
The new investigation will be carried out by the Met's Specialist Crime Directorate, which has been investigating a related phone hacking allegation since September 2010, and led by Deputy Assistant Commissioner Sue Akers from the Specialist Crime Directorate.
The original investigation was conducted by acting deputy commissioner John Yates and the Counter Terrorism Command in Specialist Operations, but the Met said today that neither would continue with the case due to the continued 'severe' threat level.
It was reported yesterday that former Downing Street director of communications Alistair Campbell had written to the Met police to say that he suspects his messages were hacked by journalists at the News of the World while he was working for Tony Blair.