Senior former and current members of the Metropolitan Police were put under the microscope of the parliamentary Home Affairs Committee yesterday over their botched investigations into phone hacking. And it did not reveal a pretty sight.

The explanations of these senior officers as to why the Met had failed to investigate phone hacking properly in 2005 – and why they had failed to re-open the investigation in 2009 when new allegations were made – were unsatisfactory. The present Assistant Commissioner, John Yates, was particularly unconvincing in accounting for his behaviour. And it was baffling to see the Met Commissioner, Sir Paul Stephenson, offering his unequivocal backing to Mr Yates last night.

These officers were also unable to account for their apparently cosy relationship with the news organisation at the centre of all this. The former Assistant Commissioner, Andy Hayman, even comically suggested at one point that it would have been more suspicious if he had failed to go to dinner with News International executives while he was investigating the firm. Yet there is nothing amusing about the allegation this week that a royal protection officer offered to sell the contact details of the Royal Family to the News of the World. Further, the revelation to the committee by the present head of the hacking investigation, Sue Akers, that only 170 of the targets (out of some 4,000) have so far been notified was also astonishing. At this rate the work will go on for years. There is clearly a case for more resources to be devoted to the operation, especially since the promised public inquiries – including one into the conduct of the police – cannot begin until criminal proceedings are over. Yesterday was only the beginning. The Metropolitan Police has many more hard questions to answer over this squalid affair.