Culture secretary Jeremy Hunt sent a "congrats" text message to James Murdoch on the day he was given the role of overseeing the News Coporation's bid to takeover BSkyB.
The Leveson Inquiry into press ethics revealed Hunt sent a message to Murdoch congratulating him on gaining European approval for the company's bid.
On the same day Hunt replaced business secretary Vince Cable in a quasi-judicial role to oversee the bid, after the latter told undercover reporters he was in a "war with the Murdochs".
Counsel for the inquiry, Robert Jay QC, asked whether Hunt's text message showed the same level of bias as Cable's comments.
Hunt replied: "As I understand it the point about a quasi-judicial rule is not that you acquire the position with your brain wiped clean. You set aside the views that you have and decide objectively and not on the policy considerations that I had previously focused on."
He admitted that he would not have sent the text if he knew he would be given responsibility for the bid, although he agreed that he knew he would be put in charge when he heard of Cable's comments.
Hunt contacted chancellor George Osborne when Cable's comments were released. Osborne replied: "I hope you like the solution."
Hunt also revealed he was "frustrated" by legal advice against taking an active role in support of the bid before he was given the role.
Hunt faced the inquiry into press ethics amid a storm of accusations that his department set up a back channel to Rupert Murdoch's company during its bid to take over BSkyB.
Many claim that Hunt's performance at the inquiry and its resulting comments could determine his political future.
He revealed the extent for his "sympathy" for the bid, which he voiced while its arbitration was Cable's responsibility. Hunt told the inquiry that he did not see a plurality issue with the bid when it was first announced.
"My view was that the Murdochs controlled BSkyB. They did not own the majority of shares, but James was the chairman and I didn't think there would be a significant change in plurality represented by buying the shares that they didn't own."
The inquiry then moved on to Hunt's initial response to the bid, which was being overseen by business secretary Vince Cable. Hunt, who said he only heard the phrase "quasi-judicial" for the first time in November 2010, said he felt he had a "duty" to be aware of the bid's progress.
Hunt was given legal advice not to get involved in the bid, after seeking advice as to what he could do to "express an opinion" to Cable.
He said:"I think I had a concern about the situation where we had this very important, very significant merger in my sector where I didn't think there was a particular problem with it, but [News Corporation] said they did feel they were facing a number of obstacles with it."
He admitted that he "may have been frustrated" as he could not take an active part in a "bid in my sector that could mean thousands more jobs would have been created".
It was revealed that Hunt communicated with his aide, Adam Smith, concerning the bid, through his personal email address, not his departmental address. He said his personal email was the only account he uses.
Jay asked Hunt whether comments on his website, which descibe him as a "cheerleader" for the Murdochs, would be seen as a true representation of his current feeling.
He said: "I would say it is not correct [that the statement reflects his current opinion] and perhaps I can correct the impression that this seems to give.
"I have a section on my site for the benefit of my constituents where I put on press articles that have been written about me. That was written by a journalist for Broadcast magazine and is not how I would describe myself."
Questions were raised about the actions of Hunt's department when the inquiry released hundreds of emails that were sent between Smith, and Frederic Michel, News Corp's public affairs director.
Smith told the inquiry that no limits were put on his contact with Michel, while he admitted that he often said things that were not Hunt's opinion.
Michel told the inquiry that he believed Hunt was "probably supportive" of the company's arguments for the bid. He denied exaggerating his relationship with the department in order to exaggerate his influence to his superiors.
Permanent secretary for the department of culture, media and sport, Jonathan Stephens, said he believed that Smith was drawn into a "web of manipulation and exaggeration".
Speaking about Smith's resignation, he told the inquiry: "I said to [Hunt] that I thought that the nature, content, extent and depth of the contact suggested by the emails revealed the previous day meant that this was far beyond what could be considered appropriate."
Throughout the inquiry, Cameron has remained defiant that Hunt was the right man to be arbiter of the bid, despite knowing that he was a supporter in principle before he was appointed.
He told ITV: "The key thing was it wasn't what [Hunt] had said in the past, it was how he was going to do the job. And I think, if you look at how he did the job, he asked for independent advice at every stage and he took that independent advice and he did it in a thoroughly proper way."
Cable was replaced by Hunt after he commented on a "war with Murdoch", appearing to void his impartiality.
He told the inquiry: "My views about this company were actually quite nuanced. I did think that there was disproportionate political influence and some politicians got too close to them."
In his witness statement he said that he felt "under siege" from News Corp, adding: "The confrontational way in which my personal views of News corporation were expressed was due to to reports coming back to me of how News Corp representatives had been approaching several of my Liberal Democrat colleagues in a way I judged to be inappropriate."