Former News International executive Rebekah Brooks and her racehorse trainer husband Charlie were arrested in dawn raids that also netted four other suspects in the spreading phone hacking scandal.
Police said the six people were arrested Tuesday on suspicion of conspiracy to pervert the course of justice. The charge is an indication that investigators may be focusing on a possible coverup of the scope of phone hacking rather than the illegal hacking itself.
It was the most arrests in a single day since "Operation Weeting" _ as the police investigation into phone hacking is known _ began arresting reporters, senior news executives, police officers and others suspected of criminal acts.
The early morning police swoop brought the scandal to Prime Minister David Cameron's immediate social circle. Cameron said at a press conference earlier this month that Charlie Brooks, Rebekah Brooks' husband who has now been arrested, was a longtime friend.
The two had gone horse riding together, said Cameron, who lives in the Cotswolds town of Chipping Norton where the couple also reside.
"I've known Charlie Brooks, the husband of Rebekah Brooks, for over 30 years and he's a good friend and he's a neighbor in the constituency _ we live a few miles apart," Cameron said after questions were raised about the propriety of the prime minister having ridden on a retired police horse that had been loaned to Rebekah Brooks.
The scandal began in 2005 with the revelation that tabloid reporters had broken into the voicemail systems of aides to the royal family in search of inside information. It mushroomed last summer with the revelation that hacking had been widespread at Rupert Murdoch's News of the World tabloid, which has since been shut.
Cameron had earlier lost his communications chief Andy Coulson because of questions that were raised about Coulson's role as editor of the News of the World when phones were hacked.
Rebekah Brooks, a one-time protege of Murdoch and also a former News of the World editor, had been arrested and set free on bail previously on charges related to the phone hacking and the corruption of officials.
In many of the earlier arrests suspects had been asked to report to various police stations for questioning, but police seem to have abandoned such lenient tactics as the scope of wrongdoing _ and the subsequent coverup _ has emerged.
Police Deputy Assistant Commissioner Sue Akers testified last month that the practice of making arrests without warning is an attempt to "secure best evidence and prevent suspects conferring or disposing of evidence."
Police did not reveal the names of the six people arrested Tuesday, but a person who had been briefed on the details said Rebekah and Charlie Brooks were among them.
News International, the British arm of Murdoch's global News Corp. empire, said its head of security, Mark Hanna, was also one of those arrested.
Police said the suspects ranged in age from 38 to 49 and that all were released on bail Tuesday evening after questioning.
The force said 23 people have been arrested as part of Operation Weeting thus far, with others facing charges as part of a related inquiry into corrupt relations between police and the press.
The embarrassing scandal, which has shown Britain's tabloid press in an extremely unflattering light, led Cameron to create a judge-led inquiry to gather evidence about media wrongdoing with an eye toward cleaning up the system.
The panel, chaired by Lord Justice Brian Leveson, has heard extensive sworn testimony about gross criminal acts committed by tabloid reporters, including descriptions of how reporters hacked into the phone of a missing girl later found murdered.
Celebrities have described extreme media harassment and said they felt stalked and trapped by overzealous, unscrupulous reporters.
The Leveson Inquiry is trying to determine why an initial police investigation into phone hacking in 2006 failed to reveal the scope of the problem.
At the time, Murdoch's executives claimed the wrongdoing was limited to one scurrilous reporter and an unprincipled private detective, both of whom were jailed.
The dormant police investigation was reopened last year after reporters were found to have hacked into the voicemail of a missing schoolgirl who was later found to have been murdered.
Faced with dozens of court cases from aggrieved victims, Murdoch's company has given apologies and cash settlements to many claimants, including actress Sienna Miller, singer Charlotte Church, and former Deputy Prime Minister John Prescott.
Murdoch has denied wrongdoing even as the scandal has claimed a number of his top lieutenants and led to the resignation last month of his son James Murdoch as chief executive of News International.
In February, Murdoch's Sun newspaper, Britain's best selling title, was hit hard as five senior staffers _ including deputy editor Geoff Webster _ were arrested as part of the inquiry into the alleged payment of bribes to police and other officials.
Rupert Murdoch had initially stood by Rebekah Brooks, a colorful figure known for her distinctive red hair, in the early days of the hacking imbroglio, but he eventually accepted her resignation shortly before her first arrest last year.
She was arrested in July on "suspicion of conspiring to intercept communications" and also on "suspicion of corruption allegations."
A spokesman for the Brookses did not return phone calls seeking comment Tuesday.
The phone hacking problem has also scuttled Murdoch's plans to purchase full control of the British broadcaster BSkyB.
Associated Press writers Raphael Satter and Robert Barr contributed to this report.