Guo Wengui, a fugitive financier and associate of Steve Bannon, is accused by federal prosecutors of engaging in a complex scheme to bilk thousands of online followers.Guo Wengui, a fugitive Chinese billionaire, was arrested on Wednesday morning in New York on charges that he orchestrated a complex conspiracy to defraud thousands of his online followers out of at least $1 billion, the authorities said.

A federal indictment unsealed in Manhattan charged that Mr. Guo and a co-defendant took advantage of Mr. Guo’s “prolific online presence” to solicit investments in various entities and programs “by promising outsized financial returns and other benefits.”

Damian Williams, the U.S. attorney for the Southern District of New York, said Mr. Guo was “charged with lining his pockets with the money he stole, including buying himself, and his close relatives, a 50,000-square-foot mansion, a $3.5 million Ferrari and even two $36,000 mattresses.” The money was also used to finance a $37 million luxury yacht, Mr. Williams said.