Ex-Metropolitan Police chief Lord Stevens has defended a scathing attack in his autobiography on former home secretary David Blunkett.
In an interview with Radio 4's Today programme, the former commissioner said he had thought long and hard before deciding to "set the record straight".
In the book, he accuses Mr Blunkett of being "duplicitous" and claims he briefed newspapers against him.
But the pair went on to have a good relationship for two years, he added.
Lord Stevens, who was Britain's most senior policeman until he retired in January, said newspaper stories used to appear about his meetings with Mr Blunkett which bore little resemblance to what had actually happened.
He said it had been a very difficult decision "whether to actually print what took place".
"But what took place was meetings and then later things that appeared in the newspapers that weren't right," he said.
He refused to be drawn on whether Mr Blunkett, who quit as home secretary in December 2004 and is now work and pensions secretary, was fit to hold public office.
"That is a matter for other people. I actually believe that there should be more truth perhaps told in terms of politics and what goes on but his position is not a matter for me," Lord Stevens said.
But he added: "I don't think there's anything wrong in actually allowing the truth to come out and saying the truth three and a half years later."
He said the two men were eventually drawn together by the "bigger issues" of the terrorist threat to the UK and went on to achieve "a lot", in partnership with the London mayor and the Metropolitan Police Authority.
Lord Stevens also defended the introduction of the Met Police's controversial "shoot-to-kill-to-protect" policy for suspected suicide bombers.
The policy has been much criticised after innocent Brazilian Jean Charles de Menezes was shot dead by police on the Tube in July following the London bombings.
Lord Stevens acknowledged the police authority had not been told about the policy change and that there had been no public discussion or debate.
But he said both the home secretary and the prime minister had been informed.
He said: "Maybe we should have discussed it but I think at the end of the day some things we keep secret about because if people know exactly what we are doing they can take action to stop it."
He backed the government's moves to strengthen anti-terrorism laws and warned some elements of the Human Rights Act might need to be overturned.
"I think the presumption must be that we start from a process where we say that the safety of the citizen comes first. The right to life comes first," he said.
"Of course we have got freedom of speech, of course we can't get into a situation where people are locked up for nothing, but if you have a proper appeals system that takes care of that, I think we are going in the right direction."