A man, thought to be ex-News of the World managing editor Stuart Kuttner, has been released on bail after he was arrested in the phone-hacking probe.
He was bailed until later this month after an interview at a London police station arranged by appointment.
The 71-year-old was arrested on suspicion of conspiring to intercept communications and corruption.
The phone-hacking scandal prompted the closure of the NoW and has resulted in 10 other arrests this year.
The Metropolitan Police investigation into phone hacking is called Operation Weeting.
Another investigation called Operation Elveden is probing allegations of inappropriate payments to officers and is being supervised by the Independent Police Complaints Commission.
Mr Kuttner held a number of senior roles at the NoW before he retired in 2009.
He was the newspaper's managing editor for 22 years and had been its deputy editor prior to that.
The BBC's June Kelly said Mr Kuttner's role would have seen him "very much involved with the finances of the paper, so he was a pivotal figure in the organisation".
"In terms of the pecking order in the company, he is way up there," our correspondent added.
Earlier, a spokesman for News International (NI) - which owned the News of the World - said the company did not know who had been arrested.
NI said it would only be told if it was a current employee.
The man is the 11th person to be arrested since Scotland Yard's latest investigation into phone hacking was launched in January.
A number of high-profile figures are among those who have been arrested, including former News International chief executive Rebekah Brooks and ex-Downing Street communications chief and former NoW editor Andy Coulson.