The publisher of the Daily Express newspaper paid thousands of pounds in fees to a private detective to dig for information on celebrities, a senior politician, a Royal girlfriend, crime victims, a media critic and owners of two rival newspaper groups, according to previously-confidential records.

The records show that the Daily Express group, owned by Richard Desmond, a London businessman whose interests also include X-rated TV channels and magazines, paid thousands of pounds in fees to a company associated with private eye Steve Whittamore for years after Whittamore pleaded guilty to breaching a British data protection law.

The records, in the form of a cryptic computerized ledger listing inquiry agencies, targets of inquiries, and amounts paid, were compiled by the publisher and submitted to a British judicial inquiry examining media reporting practices. The ledger enumerates scores of cases in which Express Newspapers paid Whittamore for information on public and private figures.

While the documents' existence was discussed at an inquiry hearing last month, its full content was not made public.

Editors and lawyers for the Express group did not respond to detailed emails requesting comment on the company's use of private detectives or what they did with such information. A company lawyer said she could not comment without instructions from her client.

The ledger contains no evidence that the Express group, or Whittamore or other private investigators it hired, engaged in the kind of deeply intrusive reporting practices, such as phone and computer hacking, for which journalists working for UK newspapers owned by Rupert Murdoch now face investigation and potential criminal charges.

The Express's hiring of private detectives was acknowledged in January by a lawyer for the newspaper group who appeared at a public hearing before Lord Justice Brian Leveson, who was appointed by the coalition government to conduct a sweeping public inquiry into journalists' methods and the relationship between British media, police and politicians.

The ledger submitted to Leveson does not identify what kind of specific information the Express paid Whittamore to dig up.

A report issued in 2006 by Britain's Information Commissioner, who investigates breaches of UK privacy law, said that 305 journalists had been identified as Whittamore customers who were driving the illegal trade in confidential personal information.

In testimony before Leveson's inquiry, Nicole Patterson, a lawyer for Express Newspapers, said that the newspapers' management had tried to match payments to private eyes with specific stories. But even when we were able to marry up the dates and stories, it's impossible to tell from the article that appeared in the newspaper what information was gathered, Patterson testified.

Patterson told the inquiry that the company's internal inquiries had determined that more often than not, the amount paid to a private investigator for a specific assignment was 75 pounds, 80 pounds, 100 pounds. It's very little money.

But records examined by Reuters show that in several specific cases, including high-profile ones, the Express group paid much larger sums to a Whittamore company.

The records show that in August 2004, for example, the publisher paid 2,687.81 pounds (including Value Added Tax) to JJ Services, described to the Leveson inquiry as a Whittamore company, for information on a target identified as Blankett. This is an apparent reference to David Blunkett, who at the time served as Home Secretary, the British government minister in charge of internal security.

A few days before the newspaper group commissioned the private detective's Blankett inquiries, Rupert Murdoch's News of the World tabloid, which was shuttered last July amid growing scandal over its reporting tactics, had published an expose of an alleged affair between Blunkett and the publisher of the Spectator, a political magazine.

Blunkett told Reuters that he had not been aware that the Express group had commissioned Whittamore to gather information on him, but added: Nothing would surprise me.

Other records show that in September 2007, the Express group paid 963.50 pounds to JJ Services for information on 'P Wilby'. This is an apparent reference to Peter Wilby, a former editor of New Statesman magazine who writes press criticism.

According to the records, the payment was made shortly after Wilby published an article in The Guardian castigating British newspapers, including the Daily Express, for excesses in their coverage of the saga of Madeline McCann, a three year-old girl who went missing while on vacation with her parents in Portugal.

Wilby said he had not been aware that the Express group had commissioned a private eye to dig up information on him. He said he assumed this must have been related to his criticism of the newspaper's McCann coverage.

Wilby acknowledged that he had been particularly rude about the Express. He said it now appears that tabloids like the Express used private detectives to dig up material on anybody who is in the news or who displeased them.

The payment records indicate that someone at the Express group also commissioned Whittamore to collect information on people connected with the owners of two UK newspaper groups which compete with the Express.

A February, 2005 ledger entry shows that the Express group paid Whittamore 2150.25 pounds for information on someone identified as Rothermere. Newspaper data banks show that in succeeding months, the Express published unflattering articles about the personal life and family history of Lord Rothermere, the hereditary House of Lords member who heads Associated Newspapers, publisher of Express Newspapers' most direct competitors, the Daily Mail and Mail on Sunday newspapers.

An Associated Newspapers representative said the company had no comment.

Another entry in the payment records shows that in March 2007, the Express group paid Whittamore 1,151.50 pounds to collect information on someone named Amiel. A few days before the payment was made, the Express ran an unflattering profile of Barbara Amiel Black, a writer and wife of Lord Conrad Black, former owner of London's Daily Telegraph, who at the time was about to go on trial in Chicago on fraud charges. Amiel had no immediate comment. Black is currently in a U.S. prison.

Other entries in the Express group payment records show that the company paid Whittamore to collect information on someone named Ciccone in January 2006, shortly before the Daily Express published an article about the personal life of pop singer Madonna, whose family name is Ciccone. A publicist for Madonna did not respond to a request for comment.

The media group paid Whittamore a modest 246.75 pounds for information on someone named Middleton shortly before publishing an article claiming that Britain's Prince William had some explaining to do to girlfriend Kate Middleton (now William's wife and Duchess of Cambridge) after he supposedly was caught kissing a former pop singer. A spokesperson said Britain's Royal Family had no comment.

(Reporting By Mark Hosenball)