Hunt's former special adviser Adam Smith will face a second day of questioning later at the Leveson Inquiry into press ethics and standards.
During his first session yesterday, it emerged that Hunt had sent a memo to prime minister David Cameron supposedly expressing his support for the Sky bid within weeks of taking on a quasi judicial role overseeing the takeover.
Smith, who stepped down last month, admitted to the inquiry that his contact with News Corp lobbyist Fred Michel had gone too far.
Also today, parliamentary secretary Jonathan Stephens, the most senior civil servant in the culture department, will be questioned on the controversy.
Stephens will particularly be quizzed over whether he gave permission for Smith to have such extensive contact with Michel during Rupert Murdoch's takeover bid.
Alongside Hunt, the spotlight is also now on Cameron, with questions over his decision to hand the adjudication of the takeover of the Sky bid to Hunt, whom he knew was in favour of the deal.
Labour has argued that Hunt, who took over the role of reviewing the Sky bid after it was stripped from business secretary Vince Cable, was not an "impartial arbiter" on the bid, and has renewed calls for him to step down.
The key memo, sent to Downing Street by Hunt while Cable was still overseeing the bid on November 19, appears to show Hunt's support for the takeover.
In the message, the culture secretary said that News Corp executive James Murdoch was "furious" about Cable's handling of the matter.
He told Cameron that it would be "totally wrong to cave in" to opponents of the deal, including many non-Murdoch newspapers and the BBC director general Mark Thompson.
Hunt stressed that the UK had the chance to "lead the way" if the Sky bid went ahead, and stressed that British media "would suffer for years" if the deal was blocked.
It is understood that the memo was sent to Smith before it went to the prime minister.
In full, Hunt's memo read: "James Murdoch is pretty furious at Vince's referral [of the bid] to Ofcom [the broadcasting watchdog]. He doesn't think he will get a fair hearing from Ofcom. I am privately concerned about this because News Corp are very litigious and we could end up in the wrong place in terms of media policy.
"Essentially what James Murdoch wants to do is to repeat what his father did with the [Sun] move to Wapping and create the world's first multi-platform media operator, available from paper to web to TV to iPhone to iPad. Isn't this what all media companies have to do ultimately?
"And if so, we must be very careful that any attempt to block it is done on genuine plurality grounds and not as a result of lobbying by competitors. The UK has the chance to lead the way… but if we block it our media sector will suffer for years… I think it would be totally wrong to cave in to the Mark Thompson/Channel 4/Guardian line that this represents a substantial change of control given that we all know Sky is controlled by News Corp now anyway."
Hunt has refused to quit and insisted that he acted with "scrupulous fairness" during the takeover review in late 2010 and first-half 2011. He is due to give his side of the story at the Leveson Inquiry on May 31.
News Corp lodged its first bid to acquire the 60.9% of Sky that it did not already own in June 2010, but dropped the bid in July 2011 after widespread pressure over the phone hacking scandal at the firm's News of the World tabloid.
> News Corp lobbyist Fred Michel: No inappropriate contact in Sky bid