London (CNN) - British Prime Minister David Cameron will cut short his trip to South Africa to deal with the nation's phone-hacking scandal, his office confirmed Monday - another day of dizzying developments that also saw a second top police official resign and the announcement of a broader police corruption probe.

The day also brought the death of a key figure in the allegations. Former News of the World reporter Sean Hoare, who told the New York Times in 2010 that former newspaper editor Andy Coulson encouraged him and other reporters to hack into the voice-mail accounts of public figures, was found dead, according to the British Press Association.

Hertfordshire police confirmed that a man's body was found and "pronounced dead at the scene shortly after." The death is "being treated as unexplained, but not thought to be suspicious," the department said in a written statement.

Britain is in an uproar over the scandal, which has cast its shadow not just across British journalism, but also Scotland Yard and the prime minister's office. It began with the phone-hacking allegations involving reporters from News of the World - which led its parent company, Rupert Murdoch's News Corporation, to shut it down - and quickly broadened into claims that journalists had paid police for confidential information.

It has led to the resignations of the commissioner and assistant commissioner of London's Metropolitan Police, known as Scotland Yard, forced the closure of one of the country's best-selling newspapers and resulted in 10 arrests. Among those arrested is Rebekah Brooks, the former News of the World editor and News International executive who resigned after the scandal broke.

It also forced the resignation of Coulson, who quit as Cameron's communications director in January as the scandal began to heat up. Coulson was News of the World editor when one of the newspaper's reporters and a private investigator were sent to prison after pleading guilty to phone hacking in 2007.

"I don't think anybody anticipated that it would snowball in this fairly dramatic way," said Jef McAllister, a London-based lawyer and former bureau chief for Time Magazine.