Scotland Yard has said that six people were arrested by detectives this morning at addresses in London, Oxfordshire, Hampshire and Hertfordshire.
Officers from Operation Weeting - the probe into cases of illegal voicemail interception by the newspapers - said that five men and one woman were arrested on suspicion of conspiracy to pervert the course of justice.
Police said that the arrests include a 43-year-old woman and a 49-year-old man in Oxfordshire. Sky News says that its sources have confirmed that they are former News of the World editor Brooks and her racehorse trainer husband Charlie.
Ex News International chief executive Brooks was arrested in July last year on suspicion of phone hacking and corrupt payments to authorities. She was bailed and has not been charged with any offence.
However, this latest action by police - the biggest single swoop so far by Operation Weeting - refers to conspiracy to pervert the course of justice. Rebekah Brooks's former PA Cheryl Carter was arrested in January on a similar charge.
The other people arrested today include a 39-year-old man held in Hampshire; a 46-year-old man arrested in West London; a 38-year-old man arrested in Hertfordshire, and a 48-year-old man arrested at a business address in East London.
Sky News crime correspondent Martin Brunt claims that Brooks and her husband were at their home in Oxfordshire when they received a very early call from police.
They are thought to be currently at a police station answering questions, although officers have not confirmed any of the arrested people's identities.
Brooks resigned as News International chief executive last year following the phone hacking scandal that led to the closure of the 168-year-old News of the World.
Her husband Charlie is a close friend of prime minister David Cameron, after the pair were at Eton together.
> David Cameron did ride Rebekah Brooks's police horse