Special counsel Robert Mueller is looking into the relationship between Donald Trump's 2016 presidential campaign and one of the most powerful lobbying groups in America, the National Rifle Association.

Sam Nunberg, a former aide to Trump's campaign, told CNN that "when I was interviewed by the special counsel's office, I was asked about the Trump campaign and our dealings with the NRA." As the news network reported, Nunberg was asked by Mueller's team of investigators about the nature of the Trump campaign's relationship with the NRA, from how he and his associates first made contact with them and arranged for Trump to speak at their national meeting in 2015 to relevant subsequent events.