Los Angeles Lakers guard Lonzo Ball has severed ties with a co-founder of Big Baller Brand over concerns that the longtime family friend has a criminal past and also has not adequately accounted for the whereabouts of roughly $1.5 million from Ball's personal and business accounts.

Ball told ESPN that he believes that Alan Foster, a friend of Lonzo's father for almost a decade who owns 16.3 percent of Big Baller Brand, had "used his access to my business and personal finances to enrich himself. As a result, I have decided to sever all ties with Alan, effective immediately."

Foster has served as the business manager of all of the Ball family's companies, including Big Baller Brand -- which was formed as a limited liability company in 2014. Foster developed a close friendship with the Ball family beginning around 2010, when Lonzo and Foster's son became friends as seventh-graders. It was Foster, Lonzo's father, LaVar Ball, has said, who helped convince him to create a shoe and apparel company featuring his three basketball playing sons rather than allow Lonzo to sign one of the guaranteed multimillion-dollar endorsement deals that had been offered by more-established shoe companies such as Nike and Adidas.

According to documents and emails reviewed by ESPN, questions about Foster's business decisions and communication were first raised last fall to Lonzo and LaVar by Lonzo's financial adviser. That adviser, Humble Lukanga of Life Line Financial Group, alleged in an October email that Lonzo's personal taxes and Big Baller's taxes could not be completed on time due to an inability to account for the whereabouts of $1.5 million.

Sources close to the Ball family told ESPN that Lonzo expressed his concerns about Foster to his father several times over the past few months but deferred to LaVar to manage the situation.

It wasn't until this week, the same sources said, that LaVar fully reviewed the email warnings and documents from Lukanga, as he had been traveling overseas with his younger sons in the fall. The sources described LaVar as "stunned" when the emails and documents were read to him. LaVar declined comment but issued a statement to ESPN calling the situation "devastating."

"I've always believed in the best in people. Regretfully, I put my complete trust in Alan Foster to manage my son's business affairs," LaVar said. "At the end of the day, family comes first, and I support Zo wholeheartedly. Together, we will make this right."

When contacted by ESPN last week to discuss his past and the Big Baller Brand, Foster initially offered to arrange an in-person meeting alongside LaVar at the Ball estate in Chino Hills, California. But repeated subsequent attempts via email, phone calls and text messages this week to reach Foster for his perspective were met with no response. Late Thursday night, he suggested meeting in person at the Ball estate on Friday, but then late on Friday suggested mid-next week because he was "super busy"; he otherwise offered no comment.

Two weeks ago, in an interview with Lonzo that covered various on- and off-court topics, an ESPN reporter asked him questions about the status of Big Baller Brand and also whether he had been aware that Foster had a prior criminal record that involved financial misdeeds. In 2002, Foster was sentenced to more than seven years in prison after pleading guilty to one count of mail fraud and two counts of money laundering as part of a scheme that defrauded 70 investors of $4 million, according to federal court records obtained by ESPN. Foster was also ordered to pay $3.7 million in restitution to victims.