Sean Hoare had blown the whistle on the extent of phone hacking at the News of the World, owned by Rupert Murdoch’s News Corp., arguing that the practice was far more common than the paper had at first admitted.
His body was found at a property in Watford, northwest of London, on Monday morning.
A spokesman for Hertfordshire Police said that Hoare’s death was “unexplained,” but it is not thought to be suspicious, according to Britain’s Press Association.
In interviews with The New York Times and the BBC, Hoare had claimed that phone hacking was “endemic” at the News of the World.
He said that then editor Andy Coulson had personally asked him to hack phones — an allegation Coulson has denied.
Hoare, who was 47, had also worked for The Sun, another Murdoch-owned tabloid.
Hoare had previously been treated for alcohol and drug problems, and had seriously injured his foot in an accident earlier this month, the Telegraph reports.
He made new allegations last week, saying that News of the World executives had paid police officers to locate “targets” by using their cell phone signal in an operation called “pinging,” the Telegraph says.
He also told a journalist from the Guardian: “There’s more to come. This is not going to go away.”
The news of Hoare's death came as the British Prime Minister David Cameron cut short a trip to Africa to fly home amid the continuing phone hacking scandal.
Also on Monday, Metropolitan Police Assistant Commissioner John Yates resigned due to growing pressure.
Former News International chief executive Rebekah Brooks is out on bail after being arrested and questioned by police on Sunday. She is scheduled to appear before a committee of Members of Parliament on Tuesday, along with Rupert Murdoch and son James.