Duke athletic director Kevin White said the school is "looking into" attorney Michael Avenatti's allegation that Nike paid Zion Williamson's mother for consulting services while her son was a top high school recruit.

Avenatti, who has been charged with attempting to extort more than $20 million in payments from Nike, alleged on Twitter on Friday night that Nike paid for "bogus" services in 2016 or 2017 "as part of a Nike bribe to get Zion to go to Duke."

In a statement to multiple outlets Saturday, White said Duke would investigate the claim as a compliance matter.

"We are aware of the allegation and, as we would with any compliance matter, are looking into it. Duke is fully committed to compliance with all NCAA rules and regulations," White wrote. "Every student athlete at Duke is reviewed to ensure their eligibility. With regard to men's basketball: all recruits and their families are thoroughly vetted by Duke in collaboration with the NCAA through the Eligibility Center's amateurism certification process."

In a statement to Yahoo Sports, Nike said it "firmly believes in ethical and fair play, both in business and sports and won't be commenting further beyond our statement."

Avenatti was charged last week in New York with extortion and bank and wire fraud. He was also charged in California with bank and wire fraud in a separate case. He has said he is innocent of the charges against him.

Williamson's stepfather, Lee Anderson, coached his stepson's grassroots basketball team, South Carolina Supreme, which was sponsored by Adidas in 2017.

Adidas sponsored summer circuit teams organized and coached by other prominent college players' families, including Indiana guard Romeo Langford's father. Similarly, Under Armour sponsored former Kansas star Josh Jackson's mother's program, and Nike sponsored a team directed and coached by former Duke star Marvin Bagley III's father.

During an October federal criminal trial in New York, in which three men were convicted for their roles in pay-for-play schemes to send high-profile recruits to Adidas-sponsored schools, one defense attorney attempted to introduce wiretap recordings, in which former Adidas consultant Merl Code and Kansas assistant Kurtis Townsend discussed what it would take for Williamson to sign with the Jayhawks.

According to a transcript of the call, which was read in court by defense attorney Mark Moore, Townsend told Code, "Hey, but between me and you, you know, [Anderson] asked about some stuff. You know? And I said, 'Well, we'll talk about that after you decide.'

"And then Mr. Code says: 'I know what he's asking for,'" Moore continued. "... 'He's asking for opportunities from an occupational prospective. He's asking for money in the pocket. And he's asking for housing for him and the family.'

"And they go on to talk. And Mr. Townsend says: 'So I've got to just try to work and figure out a way. Because if that's what it takes to get him for 10 months, we're going to have to do it some way.'"

At the time, White said Duke officials didn't believe Williamson's eligibility was in jeopardy.

"All Duke student-athletes are subject to a thorough review to ensure their eligibility," White said in a statement. "In men's basketball, for the past several summers, Duke compliance officials, top recruits and their families have engaged in and cooperated fully with the NCAA Eligibility Center's enhanced amateurism certification process. Duke works closely with the NCAA and the Atlantic Coast Conference on all compliance and eligibility matters. As we have stated in the past, we have an uncompromising commitment to compliance in athletics."

ESPN's Mark Schlabach contributed to this report.