BEIJING (Reuters) - A Chinese government housing vice-minister has lodged a $10 million defamation lawsuit against controversial billionaire Guo Wengui in New York over claims made by the exiled tycoon that she had engaged in corruption and provided sexual favors.

Billionaire businessman Guo Wengui speaks during an interview in New York City, U.S., April 30, 2017. REUTERS/Brendan McDermid

Huang Yan, vice-minister of housing and urban-rural development, filed the complaint with the New York State Supreme Court on Wednesday, saying Guo’s “false and outrageous” claims, made in a video published on YouTube in May, had caused her “severe emotional distress” and “mental anguish”.

A copy of the filing was reviewed by Reuters.

It is the first legal case brought by an individual Chinese government official since Guo began making accusations of high-level Communist Party corruption, and represents an exceedingly rare instance of a senior serving official pursuing legal action against an individual overseas.

Huang’s complaint says Guo, also known as Miles Kwok, had falsely alleged that she helped real estate developers secure project approvals by providing sexual favors to a Beijing government official, and in turn received property assets from the developers who benefited.

“Guo has falsely and repeatedly claimed that Plaintiff Huang has engaged in various nefarious actions, including, but not limited to: sex scandals and corruption,” the complaint said, adding that Guo’s statements had damaged Huang’s reputation among a large number of people, and caused many to “doubt her capabilities as a professional and a government official”.

Guo’s corruption allegations have come in a politically sensitive year, with the Communist Party keen to ensure a key five-yearly congress to be held in the autumn goes off without a hitch.

As with other defamation cases against him, Guo said he welcomed the lawsuit as an opportunity for both sides to air “facts” in the open.

“This is very normal,” he told Reuters, adding that he believed Huang had been instructed to take action by the Chinese government. “I welcome it, this is a good thing.”

Huang’s defamation suit was filed by lawyer Kevin Tung, who is also representing a group of Chinese creditors who are suing Guo for $50 million in funds they say he owes them.

“We believe that these lawsuits are meant to put pressure on Mr Kwok to stop speaking out against the People’s Republic of China,” said his lawyer Josh Schiller, of Boies Schiller & Flexner.

It adds to a long list of legal actions taken against Guo in the United States, including by movie star Fan Bingbing, conglomerate HNA Group, real estate developer SOHO China and journalist Hu Shuli.

It also comes amid a sustained and coordinated Chinese government campaign to discredit Guo, since it requested an Interpol red notice to be issued in April and declared him a criminal suspect.