By Martin HickmanRebekah Brooks was unable today to remember how The Sun established the identity of Home Secretary David Blunkett's lover hours after the News of the World being edited by her close friend Andy Coulson revealed the relationship.The News of the World knew Mr Blunkett was in a relationship with publisher Kimberley Quinn because it had been hacking her phone, but it held back her identity from its front-page scoop disclosing the affair on Sunday 15 August.However the identity of the married woman seeing the Home Secretary was an exclusive in the following day's Sun, edited by Mrs Brooks, who was having an on-off relationship with the married Mr Coulson.Under cross-examination from prosecutor Andrew Edis QC, Mrs Brooks agreed Mr Coulson "might" have told her Mrs Quinn's identity the day the NoW published the story.But she denied knowing that the NoW story had been obtained by illegal intercepting her voicemails."I didn't know it was from a hacked story," she told the Old Bailey.At first, Mrs Brooks told the court that the Sun might have worked out Mrs Quinn's identity by studying newspaper cuttings in which she which had referred to knowing Mr Blunkett.She said: "I think there were cuts [cuttings] talking about them being together, or being out together. And I think again I'm not sure I asked Andy Coulson whether we had the name right, but I certainly remember putting it to [Mr Blunkett's special advisor] Huw Evans. I remember getting the name from one of our reporters and putting it to Huw."I think I rang him and said: 'We are going to name Kimberley tomorrow' and he didn't say: 'Kimberley who - or who are you talking about?'"Mrs Brooks added: "As a journalist you do try to take a punt sometimes and try to get people to confirm what you know."She told the court: "I don't know exactly who the source is. I don't remember Andy Coulson telling me on the Sunday. There's no reason why he would have done. But there's also no reason why he thought it wouldn't have come out. He might have done...."I remember having to take a punt with Huw Evans. I didn't know it was from a phone hacking story."Mr Edis asked: "Didn't you?", to which Mrs Brooks replied: "No."Mr Edis continued: "Mr Blunkett was a friend of yours. You had become friends because of his support for Sarah's Law and you really can't remember where you go the information from to speak to Huw Evans?"Mrs Brooks said: "I spoke to lots of people that day. I just don't remember."Confronting Mrs Brooks directly, Mr Edis said: "The truth of it was that Andy Coulson told you exactly what was going on.""If Andy had told me the name, I would say," Mrs Brooks told the jury.Mrs Brooks and Mr Coulson deny conspiring to hack phones. The case resumes on Monday.