It goes from bad to worse to Guy Ritchie farce for the Murdochs, News Corp and their imploding UK newspaper group and its employees.

Not only are some of the company’s most trusted retainers in London on bail after being arrested, but the Leveson inquiry, which has provided much of the detail and names of the phone hacking cases, and given us some idea of the extent of the bribery and corruption engaged in by journalists on The Sun and The News of the World, will get to hear from Rupert and James Murdoch next month.

It seems they will be appearing on April 23 in the next part of the Leveson inquiry, which will look at the intersection of the media and politics. Overnight, from the US, UK Prime Minister David Cameron said he would appear at the Leveson inquiry if asked. He may get his chance.

At the same time Neville Thurlbeck, the former chief reporter of the News of The World has been rearrested by police a day after his former boss, Rebekah Brooks was rearrested on different charges connected to the phone hacking scandal. Thurlbeck, who looks as though he was cast by Ritchie in one of his films about London’s criminal classes, was arrested on suspicion of intimidation of a witness.

He was arrested by appointment at a central London police station at 4pm local time on Wednesday by officers working on the Operation Weeting investigation into phone hacking. That’s the same mob that rearrested Ms Brooks, and arrested her husband and four other people in a dawn raid on Tuesday morning. Brooks and her husband were bailed after 12 hours of questioning at separate police stations.

According to London media reports, James Murdoch has written a long letter to a House of Commons Committee saying he is really, really sorry for the phone hacking and other scandals, but he didn’t know a thing about them.. honest, cross my heart and hope to die.

The letter was released overnight. It is the second letter James Murdoch has sent to the Committee to state his innocence.

He denied that his resignation from the chairmanship of News International (the key company owning the London papers) was an acknowledgement of past knowledge of voicemail interception or other alleged criminal wrongdoing.

Instead, “I gave up the role of Executive Chairman of News International in order to devote myself fully to my existing roles of Deputy Chief Operating Officer and Chairman and Chief Executive Officer, International, of News Corporation, based at the company’s headquarters in New York… This move allows me to focus on the further development of News Corporation’s international television businesses, which has been my primary focus over the years, and to continue to strengthen the operational performance and risk management processes in our companies around the world.”

One of those roles involves chairing BSkyB, the UK satellite broadcasting giant 40% owned by News Corp and the key to the group’s future profit growth.

Murdoch’s letter is seven pages long and in it he expressed his deep regret over the phone-hacking scandal, but maintained he has not misled parliament over the affair.

“Clearly, with the benefit of hindsight, I acknowledge that wrongdoing should have been uncovered earlier …

“I could have asked more questions, requested more documents and taken a more challenging and sceptical view of what I was told, and I will do so in the future.”

Murdoch said that he was sorry News International did not conduct a full internal investigation after the original culture, media and sport committee report in February 2010.

“Knowing what I now know, I am sorry that the company did not conduct a full investigation into the facts in response to the committee’s report. I reiterate my personal apology to those who had their privacy invaded.”

And, in what some commentators suggest is a swipe at former senior editors and lawyers, Murdoch said:

“It would have been better if I had not relied on the people who had assured me that thorough investigations had been carried out and that further investigations were unnecessary, and the statements made by the police to the same effect. However, as I have said, I did not know about, nor did I try to hide, wrongdoing. Whilst I accept my share of the responsibility for not uncovering wrongdoing sooner, I did not mislead parliament and the evidence does not support any other conclusion.”

You have to wonder what he did as the chairman when the reports were circulating that the hacking was more widespread. Yes he was obviously told lies by executives and others, but why didn’t he take steps to check those assurances?

But the April 23 appearance at the Leveson inquiry of James and Rupert Murdoch will be fascinating. By then the House of Commons Committee should have reported and passed judgement on James Murdoch’s role in the scandal. The Committee didn’t go near the allegations about The Sun’s bribery and corrupting of officials, police and others (such as people in the Ministry of Defence).

The current stage of Leveson, which is looking at the media and the police, runs up to Easter in early April. The links between the media and the politicians, the most important of all the intersections between the media and the rest of the community, is due to start after Easter.