London's police chief has quit over his links to a former News of the World editor caught up in the phone hacking scandal.
Metropolitan Police commissioner Paul Stephenson denies any wrongdoing.
Stephenson has been criticized for hiring Neil Wallis, a former News of the World executive editor arrested last week in the scandal, as a part-time PR consultant for a year until September 2010.
He said he did not make the decision to hire Wallis, and had no knowledge of Wallis's links to phone hacking.
"I will not lose any sleep over my personal integrity," he said.
His resignation comes hours after it was reported that News International executive Rebekah Brooks was arrested - the 10th figure arrested in the growing scandal involving phone hacking by employees of Rupert Murdoch's newspapers.