By Martin HickmanClive Goodman lied to newspaper executives that he was paying police officers so that his stories were published and his contacts were paid more promptly, he said today.Expanding his defence from this morning, Mr Goodman, News of the World royal editor until 2007, said he "exaggerated the importance of stories" to improve their prominence, adding: "It would mean the source was paid more quickly."Mr Goodman told the Old Bailey that his supposed police contacts "Farrish" and "Anderson" were actually fellow newspapers journalists.Asked about an email to then editor Andy Coulson asking for payment for a "royal policeman," Mr Goodman said he was having problems getting authorisation for his cash payments, telling the court: "I was having trouble getting signatures from the managing editor. This was simply selling the idea to the editor that these were... good sources."On another email to Mr Coulson in which he referred to "one of our palace cops," Mr Goodman told the Old Bailey: "No he wasn't. I was trying to ensure payment for a contact."Mr Goodman said the newspaper's betrayal of a source in the 1990s under the editorship of Piers Morgan had convinced him to shield his real contacts from executives.A valet to the Prince of Wales had been seeking the NoW's help to land a royal book deal, but Mr Morgan and news editor Alex Marunchak had decided the confidentiality of his royal employment would be too problematic.So, Mr Goodman said, having decided Kenneth Stronach was no longer of use, "a heartless commercial decision" was made to run a story exposing him as someone wanting to sell royal secrets, leading to his arrest."What we did to Ken was pretty discreditable," Mr Goodman told the court. "One of the rules of newspaper is you don't rat on your sources, but that's what we did."Mr Goodman and Mr Coulson deny conspiring to commit misconduct in public office. The case continues.