As many as 60 people within the CIA read a cable referring to two of the 19 hijackers involved in the attacks on America on September 11 2001 before the event, yet the information was not shared with the parts of the organisation able to do anything about it, according to the agency's own internal investigation.

The revelation is one of several damning findings from the CIA's own watchdog, the inspector general, drawn up in June 2005. He accuses the CIA's top officials in the run-up to 9/11, including the then director, George Tenet, of failure to devise a strategic plan to counter Osama bin Laden in advance of the attacks.

A 19-page summary of the inspector's report was published yesterday under a new congressional law passed earlier this month, having been kept secret since it was written. It underlines the depth of infighting between the CIA and the National Security Agency which prevented clear lines of responsibility in the fight against al-Qaida.

Though the report found no evidence of misconduct or illegality, it bluntly stated that CIA officers "did not discharge their responsibilities in a satisfactory manner". The inspector, John Helgerson, went as far as to recommend further panels of inquiry into the conduct of key individuals within the agency to see whether disciplinary action should be taken against them.

Mr Helgerson said that the actions of Mr Tenet, his number two, Jim Pavitt, and the head of the counterterrorism operation, Cofer Black, should all be put under scrutiny. However, the summary reveals that the CIA director at the time of the inspector's report, Porter Goss, ruled out any further action. In a statement accompanying the declassified summary, the current director, Michael Hayden, said he agreed with his predecessor that no reprimands were called for.

The 2005 internal inquiry concludes that there was no single point of failure or "silver bullet" that would have allowed the CIA to predict or prevent the attacks of 9/11. But if systems had been in place to share and analyse critical information that could have led to a more informed assessment of the threat in the lead up to the assault.

The most direct accusation was that information on the hijackers was widely reviewed before 9/11 but was not followed up. "That so many individuals failed to act in this case reflects a systematic breakdown. There was no coherent, functioning watch-listing programme," the summary says.

Though the failings of the CIA in the run-up to the attacks on New York and Washington have been publicly examined by several congressional inquiries and the September 11 commission, the latest report gives a more stinging assessment than any previous account of the inadequate responses of individuals. Mr Tenet is singled out for particular criticism.