US lawyer Michael Avenatti, who represented porn star Stormy Daniels in her lawsuit against President Trump, has been arrested on fraud charges.
Prosecutors says he tried to extort more than $20m (£15m) from Nike, threatening to use his profile to inflict reputational harm on the firm.
In a separate case, the 48-year-old has been accused of embezzlement.
A frequent guest on TV news and talk shows, Mr Avenatti emerged as a fierce critic of Donald Trump.
At one point he said he was considering running for president himself in 2010.
What are the Nike charges about?
According to federal prosecutors in New York, Mr Avenatti met a lawyer for Nike this month and threatened to release damaging information about the company unless it made “multi-million dollar payments” to him and another, unnamed co-conspirator.
He also allegedly demanded $1.5m (£1.13m) for an individual he claimed to represent.
Mr Avenatti reportedly told the Nike lawyer that would take $10bn (£7.56bn) off his client’s market value.
He was arrested in New York on Monday, shortly after announcing that he would hold a news conference about a scandal surrounding Nike on Tuesday.
Nike said in a statement it would “not be extorted or hide information that is relevant to a government investigation”.
The company said it immediately reported the matter to federal prosecutors.
What other charges is Avenatti facing?
In another case in Los Angeles, Mr Avenatti has been charged with embezzling money from a client and defrauding a bank.
Los Angeles prosecutor Nick Hanna said Mr Avenatti describes himself as an “attorney, advocate and fighter for good” on social media, while in fact he “fights for his own selfish interests”.
He secretly collected a client’s $1.6m settlement and “loaned the client’s own money to the client”, he said.
“Mr Avenatti ‘advanced’ $130,000 to his client (…) while he waited for the supposedly late settlement money.”
Tax investigation Mark Pearson said Mr Avenatti was using this money to support a “lavish lifestyle” – one investigators estimated “to exceed over $200,000 a month”.
Mr Avenatti is also accused of falsifying documents to secure a loan from a Mississippi bank.
There is no word from Mr Avenatti on the allegations in New York or Los Angeles.
What about Stormy Daniels?
Mr Avenatti has formerly represented Stormy Daniels, who is suing the president to get out of a non-disclosure agreement she signed before the 2016 election. The non-disclosure agreement related to an affair she said he had with Mr Trump in 2006.
On Saturday, he tweeted that the president should be indicted for colluding with his former lawyer “to violate the law and commit crimes.”
Ms Daniels, in a tweet, said on Monday that she had terminated Mr Avenatti’s contract “more than a month ago… after discovering that he had dealt with me extremely dishonestly.”
“Knowing what I know now about Michael, I’m saddened but not shocked regarding his arrest.”