“During a three-week review, an N.R.A. forensic auditing firm received every single piece of information they [the N.R.A.] requested,” the statement said. “Further, the N.R.A. has had consistent access to any and all documents regarding NRATV analytics. Despite the representation set forth in their lawsuit, the N.R.A. had the personnel contract they claim AM withheld last week before they filed their lawsuit.”

The complaint details a peculiar standoff with Ackerman over Mr. North, who took over as president last year. The N.R.A. claims it was aware that Mr. North had a contract to act as the host of a web series for Ackerman, but that Ackerman has refused to provide a copy of the contract for nearly six months. Additionally, Mr. North’s counsel told the N.R.A. that “he could only disclose a copy of the contract” if Ackerman said he could, the suit says.

Subsequently, Ackerman allowed the N.R.A.’s general counsel to view the contract but not keep a copy; the viewing added to N.R.A. concerns that it had not previously received an accurate summary of the document. The association was also concerned that Mr. North’s relationship to Ackerman could “supersede his duties to the N.R.A.”

A standoff persists over additional details about the relationship, according to the complaint.

The lawsuit is further complicated by family ties. The N.R.A.’s outside lawyer, William A. Brewer III, is the son-in-law of Angus McQueen, a co-chief executive of Ackerman, and the brother-in-law of Revan McQueen, its chief executive. Ackerman called the relationships an “irreconcilable conflict of interest” and said some kind of family dispute “pervades the Brewer firm’s dealings with Ackerman McQueen.”

Travis Carter, a spokesman for Mr. Brewer’s law firm, said “the familial relationship” had “no bearing whatsoever on the N.R.A.’s litigation strategy.” He added, “Any suggestion to the contrary is contrived and a red herring.”

The suit culminates the fracturing of a more than three-decade relationship between Ackerman and the N.R.A., going back to the shaping of such memorable lines as Charlton Heston’s proclaiming that his gun would have to be pried “from my cold, dead hands.” Wayne LaPierre, the longtime chief executive of the N.R.A., had previously been a steadfast champion of the Ackerman relationship.

“I think it says something about Wayne’s character, even though he’s had a long-term working business relationship with a vendor, he’s willing to do what is right and necessary for the N.R.A. and its members,” said Todd Rathner, a board member of the rifle association.