Britain's phone-hacking scandal took a new twist on Friday as police said they had arrested a detective suspected of leaking information about the investigation into the News of the World.

Police separately said a 14th person, reportedly a former journalist at the now defunct tabloid owned by Rupert Murdoch, was arrested in connection with the original probe into the illegal hacking of mobile phone voicemails.

The Metropolitan Police Service (MPS) said in a statement that anti-corruption officers had arrested a 51-year-old officer working on Operation Weeting, the force's phone-hacking investigation.

Sky News television said he was accused of leaking information to The Guardian, the newspaper which has long been investigating the hacking at the News of the World.

"Officers from the MPS Directorate of Professional Standards Anti Corruption Unit have arrested a serving MPS officer from Operation Weeting on suspicion of misconduct in a public office relating to unauthorised disclosure of information as a result of a proactive operation," it said.

"The male detective constable, aged 51 years, was arrested at work yesterday afternoon. He has been bailed to return on 29 September 2011 pending further inquiries," it said.

The officer has been suspended as of Friday, the statement added.

Deputy Assistant Commissioner Sue Akers, the officer in charge of Operation Weeting, said the development was "hugely disappointing".

"I made it very clear when I took on this investigation the need for operational and information security. It is hugely disappointing that this may not have been adhered to," she said.

The owner of The Guardian, Guardian News and Media, said it "noted" the detective's arrest.

A spokeswoman added: "Journalists would no doubt be concerned if conversations between off-the-record sources and reporters came routinely to be regarded as criminal activity."

"In common with all news organisations we have no comment to make on the sources of our journalism."

In a separate statement, police said they had arrested a 35-year-old man by appointment on Friday at a London police station. He was bailed to return in October.

Britain's Press Association news agency named him as Dan Evans, a former News of the World feature writer previously sued by the stepmother of actress Sienna Miller over hacking.

James Desborough, the former US editor of the News of the World, was questioned by police over phone hacking on Thursday before being released on bail until October.

Police began investigating phone hacking in 2006, a probe which resulted in the jailing of private detective Glenn Mulcaire and the News of the World's royal editor Clive Goodman the following year.

Despite a steady stream of new claims, police did not reopen the probe until January this year.

A string of high-profile figures have been arrested, including former News of the World editors Rebekah Brooks and Andy Coulson, who also worked as Prime Minister David Cameron's communications chief.

The scandal has already caused the closure of the News of the World after 168 years and the resignation of the Metropolitan Police's two top officers.