(CNN) -- Rebekah Brooks testified in the United Kingdom phone hacking trial that she knowingly sanctioned payments to a public official while editor of Britain's Sun newspaper.
The payment was for a story about a plot by Iraqi dictator Saddam Hussein to bring anthrax into the United Kingdom in the 1990s. Brooks testified a public official called the Sun news desk claiming government and security services were covering up the plot.
"They were asking for money in return for the information," said Brooks, who was acting deputy editor of the Sun at the time. "I did authorize the journalist to enter into a negotiation to pay money if the story turned out to be correct."
Brooks justified the payment by saying the story was of "overwhelming public interest."
Brooks and six others face phone hacking charges, including conspiracy to intercept the voice mails of high-profile figures in Britain. All deny wrongdoing. One of the defendants is Andy Coulson, another former newspaper editor and former Downing Street communications director.
Brooks told the court she was called to a meeting at Downing Street with security service officials while the Sun team was working on the anthrax story. She said the meeting confirmed the story was true and she authorized payment to the official, later identified as a chief petty officer who was prosecuted for breach of the Official Secrets Act.
Brooks said she considered paying an official for information in another story, about expenses to members of Parliament, but procrastinated and lost the story to the Daily Telegraph.
The former News International chief executive spent most of the week being questioned about stories sourced over eight years from an official who worked at the Ministry of Defence.
Brooks denied knowing the source worked for that department, but said it "should have been brought to my attention so I could take responsibility."
The former newspaper chief said she approved payments on "a handful" of occasions between 1998 and 2009, when she edited the News of the World and later the Sun.
Brooks said she never suspected the journalist was using a public official as the source.
"I wasn't looking for corrupt payments to public officials. I was looking for public interest," she said in explaining why she approved paying around £1000 per story.
The court adjourned early Friday because Brooks was exhausted after spending six days on the witness stand. She'll testify again Monday.