New International's legal manager Tom Crone has left the company, as the fallout from the hacking scandal continues.
Last week James Murdoch suggested that Crone, a prominent lawyer, and the News of the World editor Colin Myler, who edited the paper until last week, may have misled him about the £1m payment to football chief Gordon Taylor in 2008.
The payment was the first evidence that the hacking scandal had spread beyond the royal reporter Clive Goodman.
Mr Crone was also responsible for the first internal investigation into the phone-hacking claims in 2007 and for telling MPs that phone hacking was limited to "the Goodman/Mulcaire situation".
He worked with many of the newspaper’s editors including Piers Morgan, Rebekah Brooks, Andy Coulson and Colin Myler.
Mr Crone also had regular meetings with Les Hinton, the head of News International before Mr Murdoch, to update him on legal matters.
In evidence to a parliamentary select committee on the issue two years ago, Mr Crone said: "I tasked myself with finding out what exactly had happened; what was known, who knew what other documents there might be. At no stage during their investigation or our investigation did any evidence arise that the problem of accessing by our reporters, or complicity of accessing by our reporters, went beyond the Goodman/Mulcaire situation."
Meanwhile, the US Congress is under increasing pressure to investigate the American activities of Rupert Murdoch's News Corp in the wake of the phone hacking scandal.
US ethics watchdogs called on the Senate and House of Representatives yesterday to investigate the parent company of News International and hold "thorough public hearings" on whether the voicemails of Americans had been hacked.
One group has even written to the Security and Exchange Commission (SEC) and the FBI calling for investigations into possible breaches of the Foreign Corrupt Practices Act (FCPA).
Under the FCPA, it is a crime for any American-linked company to bribe foreign officials to obtain or keep business.
Kevin Zeese, a lawyer acting for the group ProtectOurElections.org, said: "Rupert Murdoch moved to the US and became an American citizen in 1985 in order to take advantage of our laws."
Thus far, Congress is maintaining a watching brief on the issue and waiting for the tide of revelations in Britain to subside.
"We're keeping an eye on the situation, but are not planning on looking into it at this time," said Jodi Seth, press secretary for senator John Kerry, chairman of the Senate sub-committee on communications.
"For now, all that is certain is that there was hacking in Britain, which is outside of our jurisdiction."
Melanie Sloan, executive director of Citizens for Responsibility and Ethics in Washington, said that congressional investigations were essential because it was evident there was a culture of corruption within News Corp.
"It's hard to imagine that the same things have not been happening in the United States."
The tipping point, she added, would be if it became apparent that the phones of Americans had been hacked.
"Republicans are very tied to Murdoch but not at the expense of constituencies of Americans such as terror victims and soldiers," she said.
A former US government official said that the SEC, the federal regulatory agency that oversees the securities industry and stock exchanges, was very likely to look into whether News Corp had violated the FCPA.