Police assured the barrister prosecuting a News of the World reporter for phone-hacking that there was no evidence against any of the paper's other journalists, the Leveson Inquiry has heard.
David Perry QC said that at the time he saw no material that would have enabled a criminal case to be brought against Andy Coulson, then editor of the Sunday tabloid, or any other News International employees.
Former News of the World royal editor Clive Goodman and private investigator Glenn Mulcaire were jailed in January 2007 after they admitted intercepting voicemail messages left on royal aides' phones.
Mr Perry, who prosecuted the case for the Crown, told the press standards inquiry that he raised the question of whether other journalists were also involved in phone-hacking at a case conference with Scotland Yard detectives on August 21 2006.
"My recollection of this is that I asked whether there was any evidence implicating any other individual employed by News International in the criminality that we were looking at in this particular case," he said via videolink from Northern Ireland.
"I was concerned to discover whether this went further than just the particular individuals with which we were concerned, and I think I was conscious in my own mind that the question had to be whether it was journalists to the extent of the editor." He added: "We were informed there was no such evidence. I cannot recall which officer gave that reply."
The Metropolitan Police Service was widely criticised for failing to reopen its phone-hacking investigation after the Guardian published an article on July 9 2009 alleging there were more journalists and many more victims involved.
Mr Perry was asked to prepare a short note for the Crown Prosecution Service on July 14 2009 setting out the advice he was given by detectives in 2006. He wrote: "We did inquire of the police at a conference whether there was any evidence that the editor of the News of the World was involved in the Goodman-Mulcaire offences.
"We were told that there was not (and we never saw any such evidence). We also inquired whether there was any evidence connecting Mulcaire to other News of the World journalists. Again we were told that there was not (and we never saw any such evidence)."
The inquiry continues.