The Mail on Sunday continued using a private detective for 18 months after he was raided in an investigation into the illegal trade of personal information, the Leveson Inquiry has heard.
The Information Commissioner's Office uncovered a "treasure trove" of evidence linking newspapers to the sale of private data when it searched the Hampshire home of Steve Whittamore in March 2003, the inquiry has been told.
Peter Wright, editor of the Mail on Sunday, said his journalists continued using Whittamore until September 2004.
The paper's managing editor issued an instruction to staff in February 2004 that "inquiry agents" should not be commissioned to obtain information like addresses without clearance from heads of department, the inquiry heard.
Mr Wright said: "From that point onwards, Whittamore was rarely used. We stopped using him altogether in September 2004, apart from two payments which nobody can quite explain.
"But effectively he was used only on very rare occasions from February 2004, and virtually stopped altogether in September 2004."
Robert Jay QC, counsel to the inquiry, suggested that the Mail on Sunday was "running a risk" by continuing to use Whittamore after his arrest.
Mr Wright replied: "I know that our action dated from the point at which we became aware that he was going to be prosecuted.
"It was around the turn of the year 2003/04, and in February that year we took steps to stop the use of Whittamore, or at least only use him when we were extremely sure that what he was doing was legitimate and there was a good reason to do it."
Whittamore was convicted of illegally accessing data and received a conditional discharge at London's Blackfriars Crown Court in April 2005, but no journalists were prosecuted, the inquiry has heard.
