Bill Clinton, US attorney general meeting raises questions

An apparent chance meeting between former US president Bill Clinton and Attorney General Loretta Lynch, who is investigating Hillary Clinton's email usage, has created a political storm.

Lynch, however, told reporters that the rendezvous at an airport in Phoenix on Thursday, was a "chance meeting", and her discussion with Clinton did not involve anything about the investigation into the Democratic presidential nominee's use of email as Secretary of State.

"Our conversation was a great deal about his grandchildren. It was primarily social and about our travels; he mentioned golf he played in Phoenix," Lynch said.

The White House, meanwhile, said US President Barack Obama is committed to an independent investigation.

"I think the bottom line is simply that both the President and the Attorney General understand how important it is for the Department of Justice to conduct investigations that are free of political interference," White House Press Secretary, Josh Earnest, told reporters.

"The rule of law is paramount. Every American citizen should be held accountable to that rule regardless of their political affiliation, regardless of who supports them politically, regardless of what their poll numbers say," he said.

Presumptive Republican presidential nominee Donald Trump described it as "one of the big stories of this week, of this month, of this year".

Several Republican lawmakers have demanded that Lynch rescue herself from the investigation.

In a statement, conservative foundation Judicial Watch demanded that the Office of the Inspector General of the US Department of Justice investigate the meeting on Thursday.

"President Clinton is the spouse of Hillary Rodham Clinton, the former Secretary of State, who is purportedly the subject of a national security crime investigation pertaining to the mishandling of national defence information processed by Mrs Clinton's personal server during her tenure as secretary," it said.

"Attorney General Loretta Lynch's meeting with Bill Clinton severely undermined the already low public confidence in her agency's criminal investigation of Hillary Clinton," said Judicial Watch President Tom Fitton.