WASHINGTON - An internal FBI audit has found the agency violated rules more than 1,000 times while collecting data on domestic phone calls, e-mails and financial transactions in recent years, The Washington Post reported on Thursday.

The number of violations uncovered by the audit was far greater than those previously documented in a Justice Department report in March, the Post said.

The vast majority of newly discovered violations were instances in which telephone companies and Internet providers gave agents phone and e-mail records the agents did not request and were not authorized to collect, the Post said.

The agents retained the information in their files, which mostly concerned suspected terrorist or espionage activities, according to the report.

The new audit covers just 10 percent of the FBI's national security investigations since 2002, so the actual number of violations in the FBI's domestic surveillance efforts probably number several thousand, bureau officials told the newspaper in interviews.

The Justice Department audit found 22 violations in a much smaller sampling.

Of the more than 1,000 violations uncovered by the new audit, about 700 involved the provision of information by phone companies and other communications firms that exceeded what the FBI's National Security Letters had sought, the Post said.

However, some two dozen of the newly discovered violations involved agents' requests for information that U.S. law did not allow them to have, the audit found.

National Security Letters allow the FBI to compel the release of private information such as communications or financial records without getting court authority.

Their use has grown exponentially since the September 11, attacks, the Post said. More than 19,000 such letters were issued in 2005 seeking 47,000 pieces of information, it said.

"The FBI's comprehensive audit of National Security Letter use across all field offices has confirmed the inspector general's findings that we had inadequate internal controls for use of an invaluable investigative tool," FBI General Counsel Valerie Caproni was quoted as telling the Post.

Caproni said that steps have been implemented since March 2007 to fix the problem.

FBI officials said the audit found no evidence that any agent knowingly or willingly violated the laws or that supervisors encouraged such violations, the Post reported.

Rather it showed that many agents did not understand or follow the required legal procedures and paperwork requirements when collecting personal information, the Post reported.

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