A man, believed to be former News of the World news editor Greg Miskiw, has been released on bail after he was arrested in the phone-hacking probe.
He was arrested by officers from the Met Police's hacking investigation, Operation Weeting, after visiting a police station by appointment.
Police said Mr Miskiw, 61, was held on suspicion of unlawful interception of communications and conspiring to intercept communications.
He was released on bail until October.
The Metropolitan Police's Operating Weeting is investigating claims some reporters for the News of the World hacked into the messages of celebrities and public figures between 2005 and 2006.
Scotland Yard has also confirmed that the Met's Head of Public Affairs, Dick Fedorcio, has been placed on a period of extended leave.
Mr Fedorcio will be working from home while the Independent Police Complaints Commission investigates whether he has committed an act of "gross misconduct".
A statement from Scotland Yard stressed that he had not been suspended and remained on full pay but added: "To allow Mr Fedorcio to prepare for the IPCC investigation it has been agreed that he can work from home on a period of extended leave until the matter is resolved.
"Mr Fedorcio also accepts that it would be inappropriate for him to continue to come into the office whilst there was an ongoing investigation and until other staff had been interviewed."
Last month, the IPCC revealed that it had been asked to examine Mr Federcio's links to ex-News of the World executive Neil Wallis whose company was given a contract to provide PR advice to the Met in 2009.
At that time Scotland Yard was resisting calls to re-open the inquiry into phone-hacking at the News of the World.
In 2006, the paper's former royal editor, Clive Goodman, and private investigator Glenn Mulcaire were jailed for hacking into royal aides' voicemails.
Five alleged victims have reached out-of-court settlements with the newspaper, including celebrity publicist Max Clifford, who received a reported £1m.
The paper was shut down in July after it emerged that the phone of murder victim Milly Dowler may have been hacked.