The true extent of the cover-up of official failures at Hillsborough was revealed for the first time with the publication of the Hillsborough Independent Panel's report. The report said: "It is evident from analysis of the various investigations that from the outset South Yorkshire Police sought to deflect responsibility for the disaster on to Liverpool fans." The Panel found evidence that South Yorkshire Police's submissions to the Taylor Inquiry, "emphasised exceptional, aggressive and un-anticipated crowd behaviour: large numbers of ticketless, drunk and obstinate fans involved in concerted action, even 'conspiracy', to enter the stadium". The documents also reveal the "extent to which substantive amendments were made" to statements by South Yorkshire Police to remove or alter "unfavourable" comments about the policing of the match and the unfolding disaster. The report found that 116 of the 164 police statements identified for "substantive amendment" were "amended to remove or alter comments unfavourable to SYP". One police officer said he only accepted the changes because he was suffering from post-traumatic stress and that he considered it an injustice for statements to have been "doctored" to suit the management of South Yorkshire Police, the report found. The documents show, for the first time, that South Yorkshire Ambulance Service documents were "subject to the same process", the panel said. The Panel went on to say the wrongful allegations about the fans' behaviour later printed in some newspapers, particularly The Sun, originated from "a Sheffield press agency, senior SYP officers, an SYP Police Federation spokesman and a local MP". In the Commons Prime Minister David Cameron said Sun owner News International had co-operated with the report, adding that the the source for "these despicable untruths" was the agency reporting conversations with "police and Irvine Patnick, the then MP for Sheffield Hallam". The panel said the Police Federation, "supported informally by the SYP Chief Constable" sought to develop and publicise a version of events derived in police officers' allegations of drunkenness, ticketless fans and violence. "The vast majority of fans on the pitch assisted in rescuing and evaluating the injured and the dead," the panel said. The documents disclosed to the panel also revealed that further attempts were made to "impugn the reputations of the deceased by carrying out Police National Computer checks on those with a non-zero alcohol level." The panel found that access to cabinet documents revealed that in an exchange about her Government welcoming the Taylor Report, Prime Minister Margaret Thatcher expressed her concern that the "broad thrust" of the report constituted a "devastating criticism of the police". It also found that "it is evident that the primary concern of the government at the time was the potential impact (positive or negative) on the Parliamentary passage of the planned Football Spectators Bill. The documents go on to reveal the original pathologists' evidence of a single, unvarying pattern of death was "unsustainable", the panel said. The families have always disputed the accidental verdict which followed the inquest into the deaths.