There is a massive time-bomb ticking under News Corporation and Rupert Murdoch — and it has nothing to do with phone hacking by the News of the World.

Its name is Operation Elveden. It is the British police investigation that has been under way for almost a year. So far, 27 people have been arrested.

Operation Elveden is not investigating phone hacking — its remit is to lift the lid on the systemic bribery of police, army and government officials by reporters and editors, mainly at Murdoch’s beloved Sun, over more than a decade. Not £10 slings to bobbies, but a conspiracy in which police were paid to feed journalists confidential information on a production-line basis.

Watching Operation Elveden closely are US prosecutors, whose interest is whether News Corp, an American company, has breached the Foreign Corrupt Practices Act, which bars US-based corporations from paying “foreign officials” to “obtain or retain business”.

Rupert Murdoch may think that he has already endured “the most humble day of my life”, but Operation Elveden may be about to make his life a lot humbler.