0516 GMT May 19, 2019
"I did not send nor receive anything that was classified at the time," Clinton told reporters on Saturday in Winterset, Iowa, where she was holding an election campaign event, Press TV reported.
According to a US government inspector general, Clinton sent at least four messages from her private email server when she was secretary of state that contained classified information.
The four emails "were classified when they were sent and are classified now," Andrea Williams, a spokesperson for the inspector general of the intelligence community, told the Wall Street Journal.
Clinton has come under fire for using a private email account during her years at the State Department.
Clinton’s email account, clintonemail.com, was hosted by a server located at her home, making it difficult to trace the account back to her.
Using personal email does not necessarily violate rules as long as they are properly preserved, but the practice has raised doubts about her transparency.
Clinton is the front-runner for the 2016 Democratic presidential nomination, but the email controversy threatens to damage Clinton's campaign.
Some observers within the Democratic Party say the controversy has been poorly handled by Clinton’s advisers and wonder whether someone else should be their party’s candidate in the bid to succeed President Barack Obama.
Clinton has attracted plenty of criticism from Republicans for her lack of transparency and political gaffes since the administration of her husband, former President Bill Clinton.