The power struggle in the NRA struck Wayne La Pierre, executive vice president of the arms rights group, against his newly built president, Oliver North.
In a letter to members of the board on Thursday, published by the Wall Street Journal, LaPierre accused North of a conspiracy to extort, in an attempt to oust him.
"Leaders in every walk of life must often choose: between what is true and loving, between what is convenient and what is right," LaPierre wrote in a letter.
"Yesterday evening, I was compelled to face one of those who defined elections – in a style of extortionists, as an offer I could not refuse," he added.
LaPerre argued that North, who climbed to the top in the 1980s for his role in the Iran-Contra scandal, summoned a senior staff member and threatened to hand him a damning letter to board members detailing requests for sexual harassment and excessive wardrobe and travel expenses. It was not clear who was accused of these crimes.
In a statement to The Journal, a lawyer for the NRA, he said: "Many of the issues raised by the Colonel are under consideration by the NRA since the beginning of last year. In our opinion, the views that include Mr. LaPierre can be reflected wrong information about his commitment and the commitment of the NRA to good governance ".
North said, according to the letter, that if LaPerre resigned as an executive vice president, he would not send the letter to the board.
At the heart of the conflict between the two executives is a legal battle between the NRA and one of their performers, media company Ackermann McQueen.
The NRA sued Ackerman McQueen, who operates online video service NRATV earlier this month, arguing that they hid information about how they spend tens of millions of dollars given to NRA annually.
Ackerman McQueen employs the North, which hosts the documentary series NRATV.
LaPierre said in a letter that the media company paid $ 1 million a year for its work on the series, but the company has only produced three episodes last year.
Earlier this year, the NRA sent a letter to the company asking them to know what they paid for, according to LaPierre's letter.
"AM did not respond directly," LaPierre wrote. "But it seems to have indirectly reacted with trying to throw me out."
NRA did not return the request for comment.