Oliver North is out as NRA president, following a leadership dispute with longtime CEO Wayne LaPierre

LaPierre accused North of trying to smear him with "damaging" information.

Retired Marine Lt. Col. Oliver North announced on Saturday that he will not serve a second term as president of the National Rifle Association, after he said that he has lost support from the gun-right group’s board following a dispute with longtime NRA chief executive and vice president, Wayne LaPierre.

The announcement followed a letter that LaPierre sent to NRA board members on Thursday, stating that North was trying to push him out by threatening to release "damaging" information about him to the board.

The dust-up came as New York State Attorney General Letitia James announced late on Saturday that her office is investigating the NRA and has issued subpoenas. A source close to the investigation confirmed to ABC News that the probe is focused on the NRA's finances and its status as a tax-exempt non-profit.

The National Rifle Association is hosting its 148th annual meeting in Indianapolis, Indiana this weekend. President Donald Trump and Vice President Mike Pence spoke at the event on Friday.

North was not present at the annual meeting on Saturday, but delivered a letter to NRA first vice president Richard Childress to read in his absence.

"Please know I hoped to be with you today as NRA president endorsed for reelection," Childress quoted North in the letter. "I'm now informed that will not happen."

Within the letter, he made it clear that it was not his intent to step down, but rather that he was forced out.

North described being president of the NRA for nearly a year as a "privilege."

Childress' reading of North's letter was largely met with silence from the hundreds of NRA members gathered for the annual convention, according to the Associated Press.

LaPierre took the stage shortly after Childress read North's letter, and gave remarks in a prepared speech that did not address the immediate controversy.

LaPierre also stated that the challenges the organization faces right now are unprecedented, and vowed to resist efforts to curtail the rights of gun owners.

“We won’t accept it," LaPierre said. " We will resist it. We won’t give an inch."

He received two standing ovations from the crowd of about 1,000 NRA members.

North, 75, became a household name in the 1980s after his role in engineering a scheme to secretly sell weapons to Iran and divert the proceeds to Nicaragua's anti-Communist Contra rebels was exposed. The Contras were a guerrilla force fighting that country's left-wing Sandinista government at the time.

He was convicted in 1989 of obstructing Congress during its investigation, destroying government documents and accepting an illegal gratuity. Those convictions were overturned in 1991.

Neither North nor LaPierre immediately responded to requests for additional comment from ABC News.