The former managing editor of the News of the World was arrested today on suspicion of phone hacking and inappropriate payments to police, according to reports.
A 71-year-old man was released on bail tonight after being questioned at a north London police station, Scotland Yard said.
He is thought to be Stuart Kuttner, 71, who resigned as the newspaper's managing editor in July 2009.
Kuttner has previously denied his decision to quit shortly before the Guardian disclosed the News of the World paid out more than £1 million to settle cases which threatened to reveal evidence of alleged phone-hacking was related to the issue.
At the time of his resignation, he was described by then-editor Colin Myler as a man whose "DNA is absolutely integrated into the newspaper which he has represented across the media with vigour".
He was an "outstanding managing editor" who was "a major driving force behind the success of Sarah's Law", Mr Myler said.
Officers from Operation Weeting, who investigate phone hacking, and Operation Elveden, who investigate inappropriate payments to police, made the arrest, Scotland Yard said.
Alan Rusbridger, editor in chief of the Guardian, said on Twitter that it was Kuttner who had been arrested.
Several other media outlets also reported that the man being questioned was Kuttner.
He is the 11th person to be arrested since Scotland Yard's fresh investigation into phone hacking was launched in January.
These include a series of high-profile figures, including former News International chief executive Rebekah Brooks and ex-Downing Street communications chief Andy Coulson.
The scandal has already caused the closure of the News of the World after 168 years and the resignation of two top police officers, Metropolitan Police Commissioner Sir Paul Stephenson and Assistant Commissioner John Yates.
In a statement, Scotland Yard said: "The 71-year old man arrested this morning, Tuesday August 2, by Operation Weeting together with officers from Operation Elveden has been released on bail to a date later this month (August) pending further inquiries.
"The man had been arrested on suspicion of conspiring to intercept communications, contrary to Section1(1) Criminal Law Act 1977 and on suspicion of corruption allegations contrary to Section 1 of the Prevention of Corruption Act 1906."
News International said it had no comment on the arrest.
Defence counsel Tim Greaves said tonight that May-Bowles had prepared himself for the worst before sentencing.
He said: "He was aware of the sentencing guidelines and he was aware of the risks. He prepared himself for the worst and he seems composed, perhaps disappointed but composed and prepared. I would imagine that it will be very daunting."
May-Bowles has been sent to Wandsworth Prison, and although he could be eligible to be sent to an open prison the assessment process will not be carried out in time before his release, Mr Greaves said.
The legal team are trying to get the appeal dealt with quickly, but will "take instructions" on whether to continue if it cannot be processed before the end of his sentence.