House Republicans have called FBI Director James Comey to testify about Hillary Clinton's use of private email as secretary of state.
Comey will have to explain to a House committee why he recommended the likely Democratic presidential nominee should not be prosecuted.
The FBI said that over 100 classified messages were found on her email servers.
On Wednesday, US Attorney General Loretta Lynch who confirmed that no charges would be brought was accused by Donald Trump, of being bribed by the former first lady.
He said she agreed to let Clinton off the hook in return for the promise that she would keep her job if the Democrat won the election and became president.