Avenatti is also facing extortion charges in New York for allegedly trying to shake down Nike for more than $25 million.
Update 8:30 p.m. EDT March 26: In his first interview since his arrest Monday on extortion and bank and wire fraud charges, attorney Michael Avenatti told CBS News he's "scared" and "concerned" over the charges.
“Of course I'm nervous,” Avenatti said.
“I am nervous. I'm concerned. I'm scared. I feel terrible for my family. I feel bad for my friends,” he said.
He also called the charges that he tried to extort Nike “absurd.”
“There's legal experts that say I was well within the line as an aggressive attorney. There's many that say that. And the fact of the matter is, this was not extortion," he said. "People make threats all the time in connection with trying to settle a case.”
He also said on social media Tuesday evening he plans on fully cooperating with the NCAA in its investigation into college basketball corruption.
“I will fully cooperate with the NCAA to my maximum ability. Names, dates, amounts, texts, emails, bogus invoices, bank records, wire payments, cash payments, etc. - ALL OF IT. Let’s talk about the truth and facts of what really happened and let the chips fall where they may,” Avenatti said.
Update 9 a.m. EDT March 26: Avenatti thanked his supporters early Tuesday and denied in a tweet that he attempted to extort Nike.
“I am anxious for people to see what really happened,” Avenatti wrote. “We ever attempted to extort Nike & when the evidence is disclosed, the public will learn the truth about Nike’s crime & coverup.”
Avenatti was arrested Monday in a pair of federal cases in California and New York. Authorities in California charged Avenatti with bank and wire fraud. In New York, Avenatti faces charges for allegedly trying to extort Nike of more than $20 million.
His arrest came just minutes after he announced plans to hold a news conference about "a major high school/college basketball scandal perpetrated by" Nike.
Update 9:30 p.m. EDT March 25: Attorney Michael Avenatti said he expects to be "fully exonerated" on federal extortion and bank and wire fraud charges.
The Associated Press reported Avenatti made those comments after an appearance in federal court Monday evening on the charges.
He said he will “never stop fighting the good fight” against powerful people and corporations
Update 7:45 p.m. EDT March 25: A federal judge in New York ordered attorney Michael Avenatti released on a $300,000 bond, according to news reports.
Avenatti is charged with trying to extort $25 million dollars from Nike over possible wrongdoing by an amateur basketball team Nike supports, according to the Associated Press. He's also charged in a bank and wire fraud case in Los Angeles.
He made a court appearance Monday evening after his arrest earlier in the day at a law firm where he went to meet Nike executives.
Update 6:25 p.m. EDT March 25: An attorney working with Michael Avenatti on the Robert Kelly criminal case said Monday the case won't be affected by Avenatti's arrest.
Attorney Gerald Griggs said Avenatti’s arrest is “problematic” for Avenatti himself.
“However, the effect against the R. Kelly case will be minimal as the ten charges are based on four independent accusers and other information independent of Mr. Avenatti,” Griggs said in a statement.
Avenatti said last month he was representing two of R. Kelly’s alleged victims when he gave Chicago prosecutors new video evidence purportedly showing the singer abusing two underage girls.
Update 5:00 p.m. EDT March 25: Celebrity attorney Mark Geragos was the unnamed co-conspirator in Michael Avenatti's alleged plot to extort millions of dollars from Nike, according to The Associated Press.
Update 3:20 p.m. EDT March 25: In a statement obtained by CNBC, a Nike spokesperson said the company "has been cooperating with the government's investigation into NCAA basketball for over a year."
“When Nike became aware of this matter, Nike immediately reported it to federal prosecutors,” the statement said. “When Mr. Avenatti attempted to extort Nike over this matter, Nike with the assistance of outside counsel at Boies Schiller Flexner, aided the investigation.”
Authorities said Avenatti and an unnamed co-conspirator attempted to extort Nike of more than $20 million by threatening “to use his ability to garner publicity to inflict substantial financial and reputational harm on the company if his demands were not met.”
Citing a pair of unidentified sources, The Wall Street Journal reported the unnamed co-conspirator allegedly involved in the case was attorney Mark Geragos.
Update 3:05 p.m. EDT March 25: Investigators with the IRS launched a probe into Aveantti more than a year ago, after an official noticed "irregularities" while attempting to collect payroll taxes from Avenatti, U.S. Attorney for the Central District of California Nick Hanna said.
The bank and wire fraud “allegations ... paint an ugly picture of lawless conduct and greed,” Hanna said, calling Avenatti “a corrupt lawyer who ... fights for his own selfish interests by misappropriating close to $1 million that rightfully belonged to one of his clients.”
Hanna said Avenatti negotiated a settlement for one of his clients in December 2017 as part of an intellectual property dispute.
Under the settlement, Avenatti’s client was expected to get $1.6 million in January 2018. However, Hanna said Avenatti presented his client with a false settlement agreement that listed March 2018 at the date by which the payment was due. The payment was made to an account controlled by Avenatti on Jan. 5, 2018.
“Mr. Avenatti then used his client’s money to pay expenses for his own coffee business, Global Baristas LLC which did business as Tully’s coffee as well as to pay his own expenses,” Hanna said.
Avenatti was arrested Monday in New York to face federal charges on both the east and west coasts. Avenatti is facing a maximum of 50 years in prison if he’s convicted of the bank and wire fraud charges in California.
Federal prosecutors in New York also charged Avenatti in a separate case in which he was accused of attempting to extort Nike.
Update 2:20 p.m. EDT March 25: Authorities in California are providing more details Monday in the case against Avenatti.
Update 2:15 p.m. EDT March 25: Avenatti's former client, Stormy Daniels, said in a statement Monday that she was "saddened but not shocked by news reports that he has been criminally charged."
“I made the decision more than a month ago to terminate Michael’s services after discovering that he had dealt with me extremely dishonestly,” Daniels said.
Avenatti represented Daniels in her court battle to throw out a non-disclosure agreement she had signed before the 2016 presidential election. The agreement barred her from talking about a sexual encounter she said she had with Trump years before the election.
Original report: Federal prosecutors in the Southern District of New York said Avenatti attempted "to extract more than $20 million in payments from a public traded company by threatening to use his ability to garner publicity to inflict substantial financial and reputational harm on the company if his demands were not met."
The company was identified in a criminal complaint as Nike. Earlier Monday, Avenatti had announced plans to hold a press conference Tuesday “to disclose a major high school/college basketball scandal perpetrated by @Nike.”
Authorities said in a complaint filled in court that Avenatti and another person threatened to release damaging information about Nike if the company “did not agree to make multi-million dollar payments” to Avenatti and an unnamed co-conspirator.
Avenatti “threatened to hold a press conference on the eve of Nike’s quarterly earnings call and the start of the annual (NCAA) tournament at which he would announce allegations of misconduct by employees of Nike,” prosecutors said.
“Avenatti stated that he would refrain from holding the press conference and harming Nike only if Nike made a payment of $1.5 million to a client of Avenatti’s in possession of information damaging to Nike... and agreed to ‘retain’ Avenatti and (the unnamed co-conspirator) to conduct an ‘internal investigation’ -- an investigation that Nike did not request.”
Authorities said Avenatti told Nike’s attorneys in a phone call on Wednesday that, “I’ll go take ten billion dollars off your client’s market cap ... I’m not (expletive) around.”
Federal prosecutors in Los Angeles announced Monday they were charging Avenatti with wire and bank fraud in a separate case. Authorities plan to detail charges against him at a news conference scheduled for 2 p.m. EDT.
Check back for updates to this developing story.