Former News International chief executive Rebekah BrooksCredit: Barry Batchelor/PA
It is understood she was bailed at around midnight last night, to return to a London police station on a date in late October.
Brooks resigned from her post as chief executive of News International on Friday, saying she had become a "focal point" in the phone-hacking debate and was "detracting attention from all our honest endeavours to fix the problems of the past".
In a statement, the Metropolitan police confirmed that a 43-year-old woman was arrested by appointment at a London police station by officers from Operation Weeting and Operation Elveden.
Brooks was not named by police but widely identified in press coverage.
She is due to appear before the commons culture, media and sport committee tomorrow (July 19) to answer questions on phone hacking, alongside News Corporation boss Rupert Murdoch and his son and chairman of News International, James Murdoch.
At the time of writing, a spokesman for the culture, media and sport select committee said nothing had changed following Brooks' arrest.
Her arrest follows those of a series of other former News International figures, including ex-News of the World editor Andy Coulson, former royal correspondent Clive Goodman and the paper's former executive editor Neil Wallis.
Late on Friday, News Corporation also announced the resignation of Les Hinton, chief executive officer of Dow Jones and publisher of the Wall Street Journal.
In a statement, Hinton, former executive chairman of News International who had worked at the company for 52 years, said he had watched the events at the News of the World unfold "with sorrow" from New York.
"I have seen hundreds of news reports of both actual and alleged misconduct during the time I was executive chairman of News International and responsible for the company.
"The pain caused to innocent people is unimaginable. That I was ignorant of what apparently happened is irrelevant and in the circumstances I feel it is proper for me to resign from News Corporation and apologise to those hurt by the actions of News of the World."
He added that his "testimonies before the culture media and sport select committee were given honestly".