Senior Scotland Yard officer John Yates insisted today he did not try to protect News of the World journalists from phone hacking allegations.
Appearing before MPs, the acting deputy commissioner also rejected claims that he had misled Parliament in the past about the Metropolitan Police's investigation into the scandal.
Mr Yates told the Culture, Media and Sport Select Committee that Labour MP Chris Bryant had been "materially wrong" in accusations he made in the Commons earlier this month.
He maintained that the Crown Prosecution Service had advised there was only an offence where mobile voicemail messages had been intercepted before being opened by the intended recipient.
On that basis only "a very small number of cases" could be proven, he told the committee.
Asked by Labour committee member Tom Watson whether he had suppressed wrongdoing by News of the World journalists, Mr Yates said: "Absolutely not."
Mr Yates' appearance before the committee comes after he requested the opportunity to "rebut" Mr Bryant's claims that he conspired with the News of the World.
The Rhondda MP, who believes his own phone was hacked, said the officer had misled the Home Affairs select committee last September by claiming there were only eight to 12 victims of phone hacking.
Speaking to the culture committee today, Mr Yates said: "He made a number of statements in that debate about the manner in which this investigation has been undertaken by the Met, he also made several assertions which aren't correct."
The acting deputy commissioner said Mr Bryant had been "not correct" to claim that the CPS had never advised that there was only an offence under the Regulation of Investigatory Powers Act (Ripa) when voicemails were opened by the hacker first.
And he insisted that the case had only been reopened by the Met in January because of the new evidence provided by News International, owner of the News of the World.
The first investigation led in 2007 to the convictions and imprisonment of then News of the World journalist Clive Goodman and private investigator Glenn Mulcaire.
"Whatever the outcome of the future investigations the fact remains that throughout the Mulcaire and Goodman case and throughout the ensuing period until October 2010 the legal advice was unequivocal and, as I said, very proscriptive," he told the committee.
"The significance of this point is very clear.
"I have always cautioned on behalf of the original investigation that while suspects may have targeted many people as private investigators we could only actually prove the offence of voicemail interception in a very small number of cases.
"If there is a wider interpretation of what constitutes an offence under Ripa then this situation may change but that's a matter for the new investigation."