By politics.co.uk staff
Campaigning Labour MP Tom Watson will confront News Corp shareholders with fresh allegations at the company's annual general meeting later.
The culture, media and sport committee has flown to Los Angeles to participate in the meeting, which he has succeeded in gaining access to through a US trade union group.
Mr Watson pledged that his fresh revelations would reveal the unacceptable journalistic methods used by News Corp's staff extend beyond phone-hacking.
"I want to leave investors in no doubt that News Corporation is not through the worst of this yet and there are more questions for the Murdochs to answer," he said.
"We know they've used tracker devices, private investigators to follow people, as well as phone hacking. Tomorrow, I want to talk about a particular aspect of other technological surveillance, but I'll leave that for the shareholders."
Earlier this year Rupert Murdoch's questioning by Mr Watson during his grilling before the culture, media and sport committee led to the octogenarian media magnate conceding he was enduring "the most humble day of my life".
Mr Murdoch and his son James may have reason to feel more self-assured at today's meeting, despite Mr Watson's threats.
The Murdochs have been buoyed by a 12% increase in operating profits. They also control 40% of votes, meaning a defeat by independent shareholders of the reappointment of James and Lachlan Murdoch is unlikely.