President George W. Bush (File photo)

A review by top U.S. government investigators says a secret surveillance program approved by President George W. Bush after the September 11 terror attacks got too little legal review when it started.

The program included wiretaps without court approval and some unprecedented intelligence collection efforts.  News accounts say it is not clear how effective the highly controversial program was in producing useful intelligence.

The report was published Friday by five inspectors general of agencies with intelligence responsibilities: the Defense and Justice Departments, along with the Central Intelligence Agency, the National Security Agency and the Office of the Director of National Intelligence.

The report concludes information gathered by the secret program played a limited role in the FBI's (Federal Bureau of Investigation) overall counterterrorism efforts.  The report also says very few CIA (Central Intelligence Agency) analysts knew about the program and could not fully use it in their counterterrorism work.

It also questions the legal advice used by Mr. Bush to set up the program.

A Justice Department official, John Yoo, wrote a series of memos in support of the program.  News accounts of the report say those memos ignored laws restricting the government's authority to conduct electronic surveillance during wartime.

Yoo refused to be interviewed by the inspectors general, as did other Bush administration officials, including former CIA director George Tenet, former White House chief of staff Andrew Card, and former attorney general John Ashcroft.  The inspectors general did manage to speak to about 200 people inside and out of government for the investigation.

Senate Judiciary Committee Chairman Patrick Leahy is calling for a nonpartisan inquiry into the government's information-gathering programs.

Some information for this report was provided by AP.