Lord Brittan abuse inquiry 'fully justified', review finds
The Metropolitan Police investigation of a rape allegation against the late Lord Brittan was "fully justified", a review has concluded.
Scotland Yard has faced criticism over its handling of the case but the report said the alleged victim's account was "far from fanciful".
But the review - by Dorset Police - agreed the case was more "likely to lead to acquittal than conviction".
Lord Brittan died last year unaware the inquiry against him had been dropped.
The Crown Prosecution Service found in July 2013 that there was not enough evidence for a prosecution over the claim that the former Conservative peer had raped a 19-year-old female student in 1967, but the case was reopened less than a year later.
Officers interviewed Lord Brittan, who was suffering from terminal cancer, in May 2014, but no charges were brought.
Lord Brittan, whose career included two years as home secretary in Margaret Thatcher's government, died in January 2015 aged 75.
The review - carried out by Deputy Chief Constable James Vaughan from Dorset Police - found the case was examined by "skilful and tenacious" investigators. However, he did identify a number of weaknesses with the inquiry including the failure to tape an interview with Lord Brittan because recording equipment broke down.
By BBC home affairs correspondent Danny Shaw
The Vaughan review's conclusions slipped on to the Home Affairs Committee website almost unnoticed - but with so much rumour and speculation about Scotland Yard and Operation Midland, the findings of an official report should demand our attention.
Although the review identifies a series of errors with the rape inquiry, it broadly supports it.
It contradicts the view of the detective first put in charge, Paul Settle, who told MPs he disagreed with the decision to reopen the case and that questioning Lord Brittan would have been a "baseless witch hunt".
The review says there were "ample reasonable grounds" for an interview and the inquiry couldn't have properly progressed without it.
Some critics will claim the review is meaningless because it's the "police investigating the police". But it shines a rare light on secretive investigative work.
Its comment that the "operational context" the Met was working in was "extraordinary" and "very stretched" with numerous complex and high-profile cases is particularly telling.
It suggests that the strain of having to take on so many cases might affect their quality.
Amid continuing controversy about Operation Midland, the investigation into alleged abuse by high-profile figures, the Home Affairs Select Committee chairman Keith Vaz has revealed that Met Commissioner Sir Bernard Hogan-Howe has agreed to appear in front of MPs on 23 February.
Scotland Yard has declined to comment on press reports that Sir Bernard is planning to apologise to Lord Brittan's widow and to Lord Bramall.
The former head of the Army was interviewed by police in connection with allegations of historical child abuse but was told last month no further action would be taken against him.
In October, the Met published key findings from an internal report into the handling of the Lord Brittan case.
It revealed investigating officers told the complainant in April that there would not have been a prosecution for rape had Lord Brittan still been alive.
However, Lord Brittan's legal team were not told at the same time as the complainant was.
"This would have permitted them to clarify the position with Lady Brittan, for which the MPS apologised in a letter to her solicitors on 6 October 2015," the report concluded.
Scotland Yard said it had delayed telling the peer when he was alive because the Crown Prosecution Service had been asked to carry out a final review of the case.
Labour MP Tom Watson, now the party's deputy leader, has been criticised for intervening in the case and refusing to apologise to the Brittan family for his outspoken claims.
Mr Watson, a longstanding campaigner on exposing allegations of sexual abuse, wrote to Director for Public Prosecutions Alison Saunders in April 2014, calling for the case to be reviewed.
However, the letter was only passed to the police on 2 June after Lord Brittan was questioned.