Chelsea Clinton used the Clinton Foundation's resources "for her wedding", an aide to former US President Bill Clinton wrote in 2012, according to emails released by WikiLeaks.

They appear to show that Doug Band emailed John Podesta, chairman of Hillary Clinton's 2016 presidential campaign, urging him to "speak to her and end this".

"The investigation into her getting paid for campaigning, using foundation resources for her wedding and life for a decade, taxes on money from her parents..." Mr Band wrote.

"I hope that you will speak to her and end this. Once we go down this road..."

US election 2016: the race for the White House in pictures Show all 12 1 /12 US election 2016: the race for the White House in pictures US election 2016: the race for the White House in pictures Republican U.S. presidential nominee Donald Trump shakes hands with Democratic U.S. presidential nominee Hillary Clinton at the conclusion of their first presidential debate at Hofstra University in Hempstead, New York Reuters US election 2016: the race for the White House in pictures President Barack Obama embraces Democratic nominee Hillary Clinton on stage at the party's convention in Philadelphia US election 2016: the race for the White House in pictures Donald Trump's wife Melania delivered a speech at the GOP convention in Cleveland that was later found to have been cribbed in part from Michelle Obama's 2008 convention address AP US election 2016: the race for the White House in pictures Hillary Clinton talks to reporters aboard her new campaign plane on Labour Day, 5 September, her first 'press conference' since 2015 (Getty Images) US election 2016: the race for the White House in pictures Donald Trump held a joint press conference with Mexican leader Enrique Pena Nieto in Mexico City in August, hours before reiterating his harsh immigration plans at a campaign rally in Arizona Reuters US election 2016: the race for the White House in pictures Bernie Sanders officially endorsed Hillary Clinton, saying his progressive vision for ‘a transformed America’ would be ’best served by the defeat of Donald Trump’ Reuters US election 2016: the race for the White House in pictures Khizr and Gazala Khan appeared at the DNC to slam Trump for his stance on Muslim immigration, citing the case of their son Humayun Khan, who was killed in combat while serving as a Captain in the US Army in Iraq US election 2016: the race for the White House in pictures Libertarian candidate Gary Johnson is doing better in polls than any third party candidate since Ross Perot, 20 years ago Nicholas Kamm/AFP/Getty US election 2016: the race for the White House in pictures Green Party candidate Jill Stein (centre) marches with supporters in Colorado AP US election 2016: the race for the White House in pictures Hillary Clinton and Virginia Senator Tim Kaine at a rally in Kaine's home state in July, days before Ms Clinton tapped him to be her running mate Getty US election 2016: the race for the White House in pictures Trump on the campaign trail with his vice presidential pick, Indiana governor Mike Pence AP US election 2016: the race for the White House in pictures Former Ukip leader Nigel Farage appears at a Trump rally in Mississippi in August, where he told the crowd that he 'wouldn't vote for Hillary Clinton if you paid me'.

It is unclear how much money or resources Chelsea Clinton used from the Foundation for her wedding, or if any were used at all.

Earlier in the email exchange, Mr Band said he had "received a call from a close friend" of Bill Clinton who said Chelsea Clinton had told "one of the [President] Bush 43 kids" she was conducting "an internal investigation of money within the foundation".

He said "the Bush kid then told someone else who told an operative within the Republican party".

Mr Band said he had heard "more and more chatter" about Chelsea Clinton and Bari Lurie, her chief of staff at the Foundation, "talking about lots of what is going on internally to people".

"Not smart," he added.

"You are perfecting your skills for understatement," Mr Podesta replied.

It is also unclear why Chelsea Clinton was conducting an internal investigation into the Foundation.

US Election: Hillary Clinton in profile

Earlier this year, FBI agents argued the Clinton Foundation should be investigated for potentially giving donors special political access and favours.