The gaffes and missteps of Donald Trump have dominated the US election campaign, while Hillary Clinton seemed to put scandal behind her when she escaped indictment by the FBI over her use of a private email address while serving as as secretary of state. Since that reprieve, she has been content to sit back and allow her rival to self-destruct.

But another possible scandal is gathering over Mrs Clinton as the campaign enters its final stretch. It can be summed up in one phrase: donations for access.

After Bill Clinton left the presidency in 2001, he established the Clinton Foundation as a philanthropic organisation with numerous affiliates and a global reach. The Clinton Foundation’s various arms have since received $2 billion from an array of donors, including big corporations, wealthy individuals and foreign governments.