Giving evidence for a seventh day at the Old Bailey, Brooks was questioned about Operation Weeting - Scotland Yard's inquiry into the issue, which was announced in January 2011 when she was chief executive of News International.
Asked by her defence lawyer Jonathan Laidlaw QC if she expected she would be investigated, Brooks said: "No, absolutely not."
The 45-year-old has maintained that she believed any allegations of phone hacking had taken place before she became editor of the News of the World in 2002.
"Well, obviously I always had my own view, which was I didn't believe that it had," she told jurors today.
Asked about comments made by Labour MP Chris Bryant in early 2011 about the allegations, Brooks said she believed it was the result of the Sun dropping its support of the party ahead of the 2010 general election and switching to the Tories.
She told jurors: "By this time there was no love lost between Chris Bryant and he particularly had a grievance against the Sun for a story they'd written - a personal story about him."
Asked why the News of the World changed its stance and went on to admit liability for civil claims brought against it by celebrities, Brooks said it was because they had been settling them one after the other.
She said: "I think we decided that actually we should admit liability, just be open and public about it."
She told jurors that she had discussed shutting down the Sunday paper with her colleagues before they did in July 2011 as she questioned was "the brand too toxic for itself and the company".