(CNN) The National Rifle Association insisted it did not use foreign funds for election-related purposes, even as the group acknowledged it accepts money from foreign donors, new letters from the group show.

The NRA has faced a swirl of questions about whether foreign money could have been funneled through the group and used to boost the Trump campaign. The scrutiny has largely focused on the role of Alexander Torshin, a prominent Russian banker who is close to Putin and has spent years cultivating a relationship with the upper ranks of the NRA.

The NRA went all in for Trump in 2016, spending more than $30 million to back his candidacy. That's more than the NRA spent on all of its races combined -- presidential, House and Senate -- in the 2008 and 2012 election cycles, according to the Center for Responsive Politics.

There were a number of reports about efforts on Torshin's behalf to connect with Trump's team in 2016, in some instances via the NRA. McClatchy also reported in January that the FBI was investigating whether Torshin used the NRA to illegally provide funds to boost Trump.

The NRA has denied any contact from the FBI, but Oregon Sen. Ron Wyden, the top Democrat on the Senate Finance Committee, has been pressing the gun rights group for additional information about its finances.