Rupert Murdoch and his son James have been summoned to appear before members of British Parliament on Tuesday to respond to questions about the phone-hacking scandal that has engulfed their media company, News Corp.

However, since both Murdochs are US citizens, there is some doubt about their obligation to appear before any UK government committee.

Indeed, Rupert has already refused a request to appear before the House of Commons media committee, although he said he would be willing to appear at another inquiry called by Prime Minister David Cameron.

Another top figure in the ongoing affair, Rebekah Brooks, chief executive of News Corp.’s UK subsidiary, News International, has agreed to attend.

News International owned the now-defunct News of the World tabloid, the biggest casualty in the hacking imbroglio.

In a statement, MPs said: The committee has made clear its view that all three should appear to account for the behavior of News International and for previous statements made to the committee in Parliament, now acknowledged to be false. Accordingly, the committee has this morning decided to summon Rupert Murdoch and James Murdoch to appear before the Select Committee in Parliament at 2.30pm on Tuesday July 19 2011.

Should Murdoch fail to appear before this committee, he might be held under contempt by Parliament.

Deputy Prime Minister Nick Clegg has asked all three figures to do the decent thing and appear before the MPs. He also called for a fundamental reform of the British media, based on the principles of freedom, accountability, plurality, as well as independent regulation of the press

Separately, another man has been arrested in connection with the phone hacking investigation by British police. Neil Wallis, the former executive editor of the News of the World, was taken into custody arrested by officers on Thursday morning and will be interrogated on suspicions that he illegally conspired to intercept communications.