Guo Wengui said the bank pressured him into agreeing to borrow money tied to the purchase of shares in Chinese brokerage Haitong Securities.

The businessman is seeking to recover up to $500 million from UBS that he lost after the bank called in a margin loan, «Bloomberg» reported on Friday. According to Guo, the Swiss bank's' forced the sale of the stock amid a market rout and a 45 percent plunge in Haitong's Hong Kong-traded shares in 2015 wiped out his investment.

UBS said in a statement that «strongly disagrees with the claim and will vigorously defend itself.» The tycoon has been in self-imposed exile in New York since 2017, where he conducts a political agenda to bring attention to alleged corruption in the Chinese political system.

Chinese Sought Extradition

In 2017, U.S. President Donald Trump refused Chinese requests to deport Guo, a member of Trump's Mar-a-Lago resort. Guo is also known for his close ties to former White House chief strategist Steve Bannon, with whom he declared a «New Federal State of China» that «would overthrow the Chinese government.»

In August, Bannon was arrested by U.S. authorities while on Guo's $35 million luxury yacht docked in Connecticut and charged with stealing millions of dollars from the «We Build the Wall» non-profit organization.