Former News Of The World editor Rebekah Brooks and her racehorse trainer husband Charlie have been released on bail following their arrests over phone hacking.
Five of the six people detained on suspicion of conspiracy to pervert the course of justice were released this evening, Scotland Yard said.
They were bailed to return to a police station on a date in April. A 38-year-old man remains in custody.
The co-ordinated arrests were made by officers from Operation Weeting, the Metropolitan Police investigation into illegal hacking of voicemail messages.
Sky’s Glen Oglaza looks at the political implications
Brooks and her husband were at home in Oxfordshire when they had a very early call from the police, Sky News crime correspondent Martin Brunt said.
Scotland Yard said the four other men – aged 39, 46, 38 and 48 – were arrested at properties in Hampshire, London and Hertfordshire.
One of the men is head of security at News International, Mark Hanna, the company confirmed.
A number of addresses connected to the arrests are being searched, police added.
Sky sources also said Rebekah Brooks is the only one among the six that has been re-arrested in connection with the phone-hacking inquiry.
The former newspaper editor and ex-News International chief executive was arrested and bailed last summer on suspicion of phone hacking and corruption.
Her lawyer has said she denies committing any criminal offence.
David Cameron and Rebekah Brooks mix in the same social circles
Brooks was the editor of the News Of The World (NOTW) and The Sun before becoming chief executive of News International in 2009.
A public furore erupted last July after it was revealed that a private detective working for the NOTW hacked the mobile phone of murdered schoolgirl Milly Dowler.
Brooks resigned as News International chief executive last year.
Charlie Brooks, who writes for The Daily Telegraph, is an old friend of David Cameron – they were at Eton together and maintain a close friendship.
The Prime Minister was recently forced to reveal he rode a former police horse that had been loaned to the couple.
A total of 22 people have now been arrested under Operation Weeting, which has been running since January last year.
:: The phone-hacking scandal prompted the creation of the Leveson Inquiry into media ethics.