Rebekah Brooks, who edited Rupert Murdoch's British tabloids, told her trial Thursday that she had sanctioned payments to public officials for stories with an "overwhelming public interest".
Brooks told the phone-hacking trial that she had permitted such payments on a "handful" of occasions between 1998 and 2009, when she edited global media baron Murdoch's daily The Sun and its weekly sister title News of the World.
At England's Old Bailey central criminal court in London, Brooks was asked by her defence lawyer if she ever sanctioned payments to public officials, as she gave testimony.
The 45-year-old answered: "Yes."
Questioned on how many times, she replied: "A handful of occasions -- half a dozen."
"There had to be an overwhelming public interest to justify payments in the very narrow circumstances of a public official being paid for information directly in line with their jobs," she explained.
"Public interest -- I and everyone else always finds this a very difficult subject to address because it's very subjective depending on what newspaper or media organisation you're in. Each newspaper has its own interpretation.
"If there wasn't a public interest defence then it was not done because it was considered to be illegal."
Brooks denies charges of conspiring in voicemail hacking, conspiring to commit misconduct in a public office and two counts of trying to cover up evidence in order to pervert the course of justice.
Regarding claims of payments by a Sun journalist to a Ministry of Defence press officer, Brooks was asked if she knew who the reporter's source was.
"No, I didn't know," she replied.
Questioned if she knew the source was a public official, Brooks replied: "No.
"He never told me any of his confidential sources. I mean, most journalists kept their contacts and sources pretty close to their chest: it's a standard thing in the industry."
She said officials working for former prime minister Tony Blair and his then finance minister Gordon Brown would often leak information during the pair's long-running "feud" at the heart of government.
"We found both camps willing to tell particular journalists information, all of whom would be considered public officials," she said.
Brooks also told how she had regular contact with "senior level" police officers, military chiefs and figures from the MI5 and MI6 security services.
She accepted having made mistakes as an editor, saying how in the "flash of speed you can miss something perfectly obviously wrong".
Six others on trial at England's Old Bailey central criminal court in London also deny all the charges against them.
The case, which began in October and is expected to last into May, continues Friday.