Lawyers for Luigi Mangione, charged with killing UnitedHealthcare’s chief executive, are asking for details about a reported meeting between the White House and an executive with the insurer.

Lawyers for the man accused of assassinating the chief executive of UnitedHealthcare, asked a federal judge on Friday to let them investigate whether the Justice Department and company officials have cooperated to “malign and prejudice” their client.

The request is the latest turn in a festering dispute that began after Trump administration officials said repeatedly that the man, Luigi Mangione, is guilty. The judge in the case has said the comments may violate her order prohibiting the parties from making statements that could affect Mr. Mangione’s ability to receive a fair trial.