WASHINGTON (AP) -- Hillary Clinton and her team ignored clear guidance from the State Department that her email setup broke federal standards and could leave sensitive material vulnerable to hackers, a department audit has found. Her aides twice brushed aside concerns, in one case telling technical staff "the matter was not to be discussed further."
The inspector general's review on Wednesday also revealed that hacking attempts led forced then-Secretary of State Clinton off email at one point in 2011, though she insists the personal server she used was never breached. Clinton and several of her senior staff declined to be interviewed for the investigation.
Earlier this month, Clinton declared that she was happy to "talk to anybody, anytime" about the matter and would encourage her staff to do the same.
Opponents of her Democratic presidential campaign pointed to the audit as proof that Clinton has not been truthful about her private email use as fresh evidence she is not trustworthy or qualified to be commander in chief.
Campaigning in California, presumptive Republican presidential nominee Donald Trump noted solemnly that Clinton had received "a little bad news" and then railed against her "horribly bad judgment."
Clinton, also campaigning in California, didn't mention the controversy and ignored reporters' shouted questions. A spokesman for Clinton, who served as the nation's top diplomat from 2009 to 2013, declared the audit showed her email use was consistent with what others at the department have done.
The 78-page analysis, a copy of which was obtained by The Associated Press, says Clinton ignored clear directives. She never sought approval to conduct government business over private email, and never demonstrated the server or the Blackberry she used while in office "met minimum information security requirements."
Twice in 2010, information management staff at the State Department raised concerns that Clinton's email practices failed to meet federal records-keeping requirements. The staff's director responded that Clinton's personal email system had been reviewed and approved by legal staff, "and that the matter was not to be discussed any further."
The audit found no evidence of a legal staff review or approval. It said any such request would have been denied by senior information officers because of security risks.
The inspector general's inquiry was prompted by revelations of Clinton's email use, a subject that has dogged her presidential campaign.
The review encompassed the email and information practices of the past five secretaries of state, finding them "slow to recognize and to manage effectively the legal requirements and cybersecurity risks associated with electronic data communications, particularly as those risks pertain to its most senior leadership."
Clinton campaign spokesman Brian Fallon underscored that point Wednesday.
"The inspector general documents just how consistent her email practices were with those of other secretaries and senior officials at the State Department who also used personal email," Fallon said.
The audit did note that former Secretary of State Colin Powell had also exclusively used a private email account, though it did not name any other prior secretaries who had done so. But the failings of Clinton were singled out in the audit as being more serious than her predecessor.
"By Secretary Clinton's tenure, the department's guidance was considerably more detailed and more sophisticated," the report concluded. "Secretary Clinton's cybersecurity practices accordingly must be evaluated in light of these more comprehensive directives."
Republicans said Wednesday the audit showed Clinton was in clear violation of the Federal Records Act and endangered national security.
The State Department has released more than 52,000 pages of Clinton's work-related emails, including some that have since been classified. Clinton has withheld thousands of additional emails, saying they were personal.
Critics have questioned whether her server might have made a tempting target for hackers, especially those working with or for foreign intelligence services.
Separately from the State Department audit, the FBI has been investigating whether Clinton's use of the private email server imperiled government secrets. It has recently interviewed Clinton's top aides, including former chief of staff Cheryl Mills and deputy chief of staff Huma Abedin. Clinton is expected to be interviewed.
Clinton has acknowledged in the campaign that the homebrew email setup in her New York home was a mistake. She said she never sent or received anything marked classified at the time, and says hackers never breached the server.
The audit said a Clinton aide had to shut down the server on Jan. 9, 2011, because he believed "someone was trying to hack us." Later that day, he said: "We were attacked again so I shut (the server) down for a few min."
The next day, a senior official told two of Clinton's top aides not to email their boss "anything sensitive," saying she could "explain more in person."
On CBS' "Face the Nation" this month, Clinton said, "I've made it clear that I'm more than ready to talk to anybody, anytime. And I've encouraged all of (my staff) to be very forthcoming."
The audit said four of her closest State Department aides -- Mills, Abedin, policy chief Jake Sullivan and strategy aide Philippe Reines -- all declined interview requests.
Associated Press reporters Stephen Braun, Chad Day, Jack Gillum in Washington and Lisa Lerer in Los Angeles contributed to this report.
Read the State Department Inspector General's report at http://apne.ws/1qJYhjw
Follow Michael Biesecker on Twitter at https://twitter.com/mbieseck and Bradley Klapper at https://twitter.com/bklapperAP