Chaos reigned briefly during the appearance of Mr Murdoch - and his son James - before the Culture, Media and Sport Committee, as he was pelted with a shaving foam pie.
As the protestor was led from the room by police, wearing a checked shirt and with foam on his face, Ms Deng picked up the empty paper plate and angrily hurled it after him.
When the hearing resumed, Labour MP Tom Watson - a vociferous critic of News International - concluded his questioning by telling Rupert Murdoch: "Your wife has a very good left hook."
Committee chair John Whittingdale apologised for the "wholly unacceptable treatment" he had received from a member of the public.
Previously, the 80-year-old media mogul had declared "this is the most humble day of my life", and added that he was "more than prepared" to answer the questions put to him over the scandal.
It was a change of tack from his declaration a week ago that he would use the hearing to expose the "total lies" levelled at his company - a move he did, however, follow up with full-page apologies taken out as advertisements in rival newspapers.
The Murdochs only agreed to attend Tuesday's hearing after they were ordered to do so, or risk being fined or even jailed - the committee has the power to summon anyone, regardless of their nationality, although they don't have to stay in the UK before or after a hearing.
The scandal began when it emerged the News of the World newspaper had used phone hacking to obtain stories, with politicians, sports stars and celebrities among those targeted.
It then escalated with new details emerging almost daily - including that young murder victim Milly Dowler and the families of soldiers killed in action also had their phones hacked.
I was absolutely shocked, appalled and ashamed when I heard about the Milly Dowler case only two weeks ago.
Rupert Murdoch
The revelations prompted the eventual closure of the News of the World and the resignations of former editor turned News International chief executive Rebekah Brooks and senior Met Police officers.
When asked by the committee about Ms Brooks' 2003 admission that police were paid for information, Rupert Murdoch said he was now aware of that but hadn't been at the time.
"I'm sorry, if I can just say something and this is not as an excuse, maybe it's an explanation of my laxity," he added.
"The News of the World is less than 1% of our company. I employ 53,000 people around the world who are proud and great and ethical and distinguished people, professionals.
"I'm spread watching and appointing people whom I trust to run those divisions."
His son James was asked by committee chair John Whittingdale which News of the World staff, apart from Clive Goodman, were involved in phone hacking.
"There have been a number of arrests of former News of the World employees," James Murdoch replied.
"These are matters for current criminal investigations and I think understandably it's difficult for me to comment in particular on some of those individuals."
It is revealing in itself what he (Rupert Murdoch) does not know and what executives chose not to tell him.
Labour MP Tom Watson
Earlier former Metropolitan Police Commissioner Sir Paul Stephenson, assistant commissioner John Yates and Scotland Yard's director of public affairs Dick Fedorcio gave evidence to the Commons Home Affairs Committee as the controversy continues to dominate headlines.
Meanwhile, Northern Ireland MP Nigel Dodds has added his voice to calls for the terms of reference of the judge-led inquiry into phone hacking to be widened.
"The allegations against News International have caused public revulsion throughout the country. It is entirely right that they should be investigated fully and that action should follow from any illegality that is discovered," the DUP deputy leader said.
"However it is not acceptable that the terms of reference for the judge-led inquiry should be limited only to phone hacking and only to newspaper outlets."
Mr Dodds added: "In order to establish the depth and extend of any illegal behaviour, it will be necessary to ensure that the inquiry examines the role played by other media outlets - like television and radio - in the illegal hacking of people's phones.
"It will also be necessary to examine not only phone hacking but also email account hacking and other illegal practices such as 'blagging', which has been used by some in the past to gain access to bank account details."
The chairmen of seventeen Parliamentary Select Committees and other senior back-bench MPs are calling for such expansion to the inquiry to go ahead.
Rebekah Brooks is also appearing before the Commons committee on Tuesday evening, where she has denied sacking legal expert Tom Crone - saying he left because the News of the World had closed.
She also insisted that people at the News of the World had consistently denied the allegations in various internal investigations.
"It was only when we saw the Sienna Miller documentation that we realised the severity of the situation," she said.