House Republicans have called FBI Director James Comey to testify about Hillary Clinton's use of private email as secretary of state, BBC News reports.

Comey will have to explain to a House committee why he recommended the likely Democratic presidential nominee should not be prosecuted.

Over 100 classified messages were found on her email servers, the FBI said.

On Wednesday, July 6 U.S. Attorney General Loretta Lynch confirmed that no charges would be brought.

Lynch was accused by Republican Donald Trump, who is likely to do battle with Clinton for the White House, 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.

The news that the attorney general met former President Bill Clinton, Clinton's husband, last week on the tarmac of an airport in Arizona prompted accusations by Republicans of a stitch-up.

On Tuesday, the FBI said Clinton and her staff were "extremely careless" in handling classified materials but there was no evidence of intentional wrongdoing.

Comey's statement contradicted Clinton who previously said she had not knowingly sent or received classified material from her private email account.

He will testify on Thursday before the House Committee on Oversight and Government Reform, led by Republican Jason Chaffetz.

"The FBI's recommendation is surprising and confusing," Chaffetz said.

"The fact pattern presented by Director Comey makes clear Secretary Clinton violated the law," he said. "Individuals who intentionally skirt the law must be held accountable."

A statement from Clinton's campaign team called it "yet another taxpayer-funded sham of an inquiry to try to hurt Hillary Clinton politically".