Stephenson was linked to former News of the World deputy editor Neil Wallis in reports which said the police chief accepted a five-week stay earlier this year at a luxury health spa where Wallis worked as a public relations consultant.

The force is already facing questions about why it hired Wallis as an advisor two months after he quit the tabloid. Wallis was arrested last week.

"I have taken this decision as a consequence of the ongoing speculation and accusations relating to the Met's links with News International at a senior level and in particular in relation to Mr. Neil Wallis who as you know was arrested in connection with Operation Weeting last week," he said.

But he insisted he had committed no impropriety.

"Let me state clearly, I and the people who know me know that my integrity is completely intact," Stephenson added.

"I may wish we had done some things differently, but I will not lose sleep over my personal integrity."

Stephenson maintained he had "played no role" in Wallis's employment and "unequivocally did not know" that the former deputy editor was involved in phone hacking, according to Sunday's statement.

The Scotland Yard boss added he had done nothing wrong in staying at the luxury resort as he recovered from a leg injury.

"I am extremely happy with what I did and the reasons for it -- to do everything possible to return to running the Met full time," he reasoned.

However, the chief said that with the 2012 London Olympics on the horizon, it was "not the time for ongoing speculation about the security of the position of the commissioner."

Police have been under intense scrutiny over their decision to close the initial phone-hack investigation after the imprisonment of private investigator Glenn Mulcaire and News of the World royal editor Clive Goodman in 2007.

Stephenson, who took control of the force in 2009, said he had "no knowledge of, or involvement," in the original 2006 investigation.

"I do not occupy a position in the world of journalism," he said.

"I had no knowledge of the extent of this disgraceful practice and the repugnant nature of the selection of victims that is now emerging."

The outgoing boss admitted the force's "severe discomfort" over its handling of the case, but thanked those who spoke out for "giving us the opportunity to right the wrong done to victims".