Dallas Cowboys running back Darren McFadden has sued his longtime business manager, saying he misappropriated and mishandled money throughout his NFL career, including $3 million lost in a bitcoin business venture.

The $15 million lawsuit was filed Tuesday against Michael Vick of Mabelvale, Arkansas, and 10 unknown others named only as "Doe."

Vick, who is not the former NFL player, told The Associated Press on Thursday that he hadn't seen the lawsuit and declined to comment immediately.

McFadden's lawsuit said that two days after his 2008 debut with the Oakland Raiders, Vick used fraudulent documents to gain power of attorney and later fabricated fictitious financial records to hide what he was doing. The former University of Arkansas running back said he discovered the fraud when Vick tried to sell him a building allegedly bought with McFadden's own funds.

Darren McFadden claims in a lawsuit that former business manager Michael Vick used fraudulent documents to gain power of attorney and later fabricated fictitious financial records to hide what he was doing. Rob Foldy/Getty Images

"Rather than securing for Plaintiff a lifetime of financial security as Defendant Vick promised Plaintiff, Defendant Vick covertly used Plaintiff's income as his personal slush fund to subsidize his own lifestyle and expenses and to invest in his own projects," the lawsuit said.

The lawsuit, filed in federal court in Little Rock, also said McFadden revoked Vick's power of attorney last month. McFadden told the Dallas Morning News on Thursday that he fired Vick as his business manager about six to seven months ago.

McFadden told the newspaper that Vick was "an old family friend that we knew growing up forever and ended up trusting him to do my finances and it didn't work out right for me.

"It's just one of those deals with me as a young guy I wasn't on top of my finances like I should have been and I trusted somebody to take care of everything for me and I don't feel like at the time he had my best interest."

Vick allegedly told McFadden that in order to safeguard his money, Vick needed to be "further empowered" to help the player avoid the "financial disasters that tend to flow from unsound spending habits, poor management, or speculative financial advice," the lawsuit said.

McFadden gave Vick power of attorney on Aug. 10, 2008.

McFadden, who was the fourth pick of the 2008 NFL draft, had a $60 million, six-year contract with the Raiders at that time.

The two-time Heisman Trophy runner-up joined the Cowboys prior to the 2015 season after seven disappointing years in Oakland, where he averaged just over 600 yards per season, with a high of 1,157 in 2010. His Dallas deal was reported to be worth up to $5.9 million over two years.

The Associated Press contributed to this report.