A whistleblower in Britain's phone-hacking scandal, former News of the World reporter Sean Hoare, was found dead at his home on Monday but there appeared to be no suspicious circumstances, police said.
Hoare alleged in interviews with The New York Times newspaper and the BBC last year that the tabloid's former editor Andy Coulson, who went on to become press chief to British Prime Minister David Cameron, knew about voicemail hacking.
The 47-year-old was found dead early on Monday at his home in Watford, north of London, Hertfordshire Police said in a statement.
"At 10.40 am today (Monday) police were called to Langley Road, Watford, following the concerns for welfare of a man who lives at an address on the street," the force said.
"Upon police and ambulance arrival at a property, the body of a man was found. The man was pronounced dead at the scene shortly after.
"The death is currently being treated as unexplained, but not thought to be suspicious. Police investigations into this incident are ongoing."
The Guardian newspaper said Hoare had long-term drink and drug problems.
Hoare claimed that Coulson knew about the paper's staff eavesdropping on private messages.
"Everyone was doing it," he told the Guardian's Nick Davies. "Everybody got a bit carried away with this power that they had. No one came close to catching us."
His claims were passed to Scotland Yard but they said he declined to give evidence.
Hoare blamed the intense pressure of working at the mass-circulation tabloid for his descent into addiction.
"There is so much intimidation," he explained to Davies. "In the newsroom, you have people being fired, breaking down in tears, hitting the bottle."
The former journalist was sacked by the News of the World in 2005 over his drug and drink problems but later accused the paper of paying him to go out and take drugs with celebrities.
Hoare, who worked alongside Coulson on the Sun's showbusiness page, had become increasingly paranoid and "was always hiding in the flat with his curtains drawn," neighbours said on Monday.