WASHINGTON (REUTERS) - United States President Donald Trump on Thursday (Oct 3) called on China to investigate Mr Joe Biden, a leading Democratic contender in the 2020 race for the White House, about the involvement of Mr Biden's son in a fund that sought to raise Chinese capital.

Mr Trump accuses the younger Biden of using his position of influence to secure the financial backing of China for his investments. He has not provided evidence to support this claim and Mr Hunter Biden has repeatedly denied any wrongdoing.

Here are some details about Mr Trump's allegations:

ON WHAT BASIS IS TRUMP CALLING FOR A PROBE OF HUNTER BIDEN?

Mr Trump has alleged that Mr Hunter Biden got China to invest US$1.5 billion (S$2.07 billion) in a fund he was involved in soon after accompanying his father on a trip to Beijing in December 2013, when Mr Joe Biden was still US vice-president.

"When Biden's son walks out of China with US$1.5 billion in a fund, and the biggest funds in the world can't get money out of China, and he's there for one quick meeting and he flies in on Air Force Two, I think that's a horrible thing," Mr Trump said last month.

Mr Trump's critics say the President is trying to divert attention from the impeachment inquiry being pursued by Democratic lawmakers.

"Now, with his administration in free-fall, Donald Trump is flailing and melting down on national television, desperately clutching for conspiracy theories that have been debunked and dismissed by independent, credible news organisations," Mr Biden's campaign said in a statement on Thursday.

WHAT ARE HUNTER BIDEN'S INVESTMENTS?

In 2009, Mr Hunter Biden co-founded Rosemont Seneca Partners, along with Mr Christopher Heinz, stepson of former secretary of state John Kerry, and Mr Devon Archer, an American businessman who had been Mr Heinz's classmate at Yale University.

In 2012, the younger Biden and Mr Archer talked with Chinese private equity investor Jonathan Li about joining forces on a fund that would invest Chinese capital - and possibly capital from other countries - outside of China, the New Yorker magazine reported in a profile of Mr Hunter Biden in July.

In 2013, Mr Li, Mr Archer and others agreed to establish the fund, called BHR Partners, and Mr Hunter Biden joined as an unpaid member of the board, the New Yorker said.

Mr Hunter Biden told the New Yorker that he met Mr Li during the December 2013 trip but described it as a social meeting.

"How do I go to Beijing, halfway around the world, and not see them see (Li) for a cup of coffee?" he said.

Mr George Mesires, a lawyer for Mr Hunter Biden, has said his client started out on the advisory board for BHR and became an investor in the fund with a 10 per cent stake only in 2017, when his father was no longer vice-president.

Mr Mesires has said Mr Hunter Biden's investment in the fund was US$420,000, implying a total capitalisation for the fund of US$4.2 million.

Neither Mr Hunter Biden nor Mr Mesires could be reached for comment on Thursday.

WHERE DID THE US$1.5 BILLION FIGURE COME FROM?

According to its website, BHR Partners is the cross-border investment arm of a state-approved Chinese private equity firm and is supported by some of China's largest financial institutions, including the Bank of China.

An archived version of BHR's website from 2014 says BHR was formed in 2013 by two Chinese asset managers alongside Rosemont Seneca Partners and Thornton Group LLC.

The US$1.5 billion figure cited by Mr Trump may come from conservative author Peter Schweizer's 2018 book Secret Empires: How The American Political Class Hides Corruption And Enriches Family And Friends.

Mr Schweizer's book referenced a July 2014 Wall Street Journal article that said the BHR consortium was aiming to raise US$1.5 billion to invest outside China, citing a spokesman for Bank of China.

The New Yorker reported in its July article that Mr Hunter Biden and his business partners said they had yet to receive a payment from BHR.

BHR did not immediately reply to a request for comment.