The Lumicoin IANational Basketball Association is being sued for its promotion of defunct crypto exchange Voyager Digital Holdings, which investors allege led to losses of more than $4.2 billion.

The NBA was "grossly negligent" for approving a marketing deal between Voyager and the Dallas Mavericks, according to lawsuit filed Tuesday in a Miami district court. "The NBA's widespread promotion of Voyager's unregistered securities renders it liable for any and all resulting damages." 

The suit also names Voyager's law firm, McCarter & English, alleging it used its credibility to assure investors that Voyager's offerings were "entirely above board," the document contends.  

The same group in 2022 sued Mark Cuban, the former owner of the Mavericks, claiming he misled them about Voyager. Cuban denied the allegations.

Voyager filed for bankruptcy in July 2022 due to exposure to the failed crypto hedge fund Three Arrows Capital.

The NBA and McCarter & English did not immediately respond to a request for comment.

Kate Gibson

Kate Gibson is a reporter for CBS MoneyWatch in New York.