Since her use of a private email server was made public last year, Democratic presidential candidate Hillary Clinton has insisted she turned over all work-related emails to the State Department to be released to the public. But after 14 months of public scrutiny and the release of tens of thousands of emails, an agency watchdog's discovery of at least three previously undisclosed emails has renewed concerns that Clinton was not completely forthcoming when she turned over a trove of 55,000 pages of emails. And the revelation has spawned fresh criticism from presumptive Republican presidential nominee Donald Trump. The three messages which appear to have been found among electronic files of four former top Clinton State Department aides included Clinton's own explanation of why she wanted her emails kept private. In a November 2010, email, Clinton worried that her personal messages could become accessible to outsiders. Two other messages a year later divulged possible security weaknesses in the home email system she used while secretary of state. The Clinton campaign has previously denied that her home server was compromised. Yesterday, Clinton, who has called her use of a private email server "a mistake," said she had been forthcoming with her personal emails and said she believed her use of a private email account was allowed. "I have provided all of my work-related emails, and I've asked that they be made public, and I think that demonstrates that I wanted to make sure that this information was part of the official records," Clinton said, according to an interview transcript provided by ABC News. Most of Clinton's emails have been made public by the State Department over the past year due to both a court order and Clinton's willingness to turn them over. But hundreds were censored for national security reasons and 22 emails were completely withheld because the agency said they contained top secret material, a matter now under investigation by the FBI. Clinton said in March 2015 that she would turn over all work-related emails to the State Department after removing private messages that contained personal and family material. "No one wants their personal emails made public and I think most people understand that and respect their privacy," she said after her exclusive use of private emails to conduct State Department business was confirmed by media reports. Senate investigators have asked for numerous emails about Clinton's server as part of their own inquiry into Clinton's email practices in recent months, but they didn't get copies of key messages made public by the State Department's own watchdog this week, a senior Republican senator said yesterday.