The arrests yesterday morning of six people, including the former chief executive of News International, Rebekah Brooks, and her racehorse-trainer husband, coincided not just with the opening day of the Cheltenham Festival – embarrassment for them – but with the start of the official visit of their friend David Cameron to the United States – embarrassment for him. The association between the Brookses and the Camerons, as members of the so-called Chipping Norton set, has been a recurrent theme of the phone-hacking scandal, and it is refusing to go away.

Little has illustrated the links more piquantly than the saga of Raisa, the retired police horse (may she rest in peace). Raisa returned to haunt proceedings yesterday with the appearance before the Leveson Inquiry of Dick Fedorcio, director of public affairs at the Metropolitan Police, and currently on leave. Mr Fedorcio cleared up one mystery when he said it was he who had negotiated the loan of the horse to Ms Brooks. But he created another, when he said he had discussed the loan with her and the then Met Commissioner, Sir Ian Blair, over lunch.

Sir Ian – now Lord Blair (an elevation that might offer more food for thought) – had told the inquiry that he had lunched with Ms Brooks, but had no recollection of discussing the horse. Nor is Lord Blair the only person with a memory tending to blankness on matters equine. The Prime Minister himself professed uncertainty about his relationship with Raisa, only to clarify that he had indeed ridden her, on an outing with his old schoolfriend, Mr Brooks.

These wheels within wheels spun a little faster yesterday with another disclosure from Mr Fedorcio: that he had received a food hamper from Andy Coulson (then News of the World editor, soon to be Mr Cameron's media chief) "as a thank-you" for dealing with the paper's demands. Of course, it is not unknown for the elite in any society to move in similar circles and for their paths to have crossed as they forged their upward paths. But the associations that are emerging between the Cameron coterie, the Metropolitan Police and the Murdoch newspapers raise questions that cry out ever more insistently for answers.