(CNN) - Special counsel Robert Mueller is looking into the Trump campaign’s close relationship with the National Rifle Association.
“Part of his appeal was that this guy was going to win at all costs,” said Sam Nunberg, a former Trump campaign aide. “When I was interviewed by the special counsel’s office, I was asked about the trump campaign and our dealings with the NRA.”
Mueller’s investigators were interested in how Trump and his early operatives first formed a relationship with the NRA, how Trump wound up speaking at the group’s 2015 annual meeting, just months before announcing his presidential bid, according to Nunberg.
The questions from Nunberg’s interview in February 2018 are the first indication Mueller has been probing the Trump campaign’s ties to the powerful gun rights group and was still asking questions about it as recently as a month ago.
While the NRA hasn’t been accused of any wrongdoing by law enforcement, it has come under scrutiny for its ties to Russians and massive support of Trump in 2016.
Trump was helped along by his son, Donald Trump Jr., an avid outdoorsman who played a role in his father building ties to the NRA.
“They love the NRA more than anyone I know. They happen to be my sons. They’re lifetime members,” Trump said.
Donald Trump Jr. testified to the house intelligence committee in December 2017 that he and Alexander Torshin - a former Russian banker and lifetime NRA member who was sanctioned by the U.S. Treasury Department last year - “exchanged casual hellos” on the sidelines of the 2016 NRA meeting.
Trump Jr. denied discussing any details of the upcoming presidential election with Torshin.
One Russian who had dealings with the NRA is Maria Butina, who recently pleaded guilty to engaging in a conspiracy against the U.S.
As part of her plea deal in December, Butina admitted she tried to build relationships with NRA members as a way to infiltrate Republican political circles and influence U.S. relations with Russia.
She worked at the behest of Torshin. Years before her arrest, Butina even managed to ask Trump about his views on Russia at a political event.
“If you will be elected as a president, what will be your foreign politics, especially in the relationships to my country?” she said.
“I believe I would get along very nicely with Putin, OK?” Trump said.
Despite Trump’s prior support for a ban on assault weapons, he still became a darling of the NRA.
The gun rights group shelled out more than $30 million to boost Trump in 2016, according to the Center for Responsive Politics.