The supposed ringleader of a Nationals branch stacking operation that resulted in dozens of alleged neo-Nazi and white supremacists infiltrating the party won't be investigated by the organisation's ethics committee.

The man, who many within the party hold responsible for stacking the 2018 NSW Young Nationals annual conference with people tied to alt-right organisations, was cleared of having neo-Nazi links by an initial internal investigation, senior party sources have told AAP.

The speedy investigation also cleared more than 20 others - including one federal minister's staffer - without referring them to the party's Constitution and Ethics Committee.

A further 17 people implicated in alleged neo-Nazi activity will be subject to the ethics committee investigation, which is expected to take place before the end of the week. It is understood many of those will be asked to leave the party.

The names of those cleared and the 17 people referred to the committee are detailed in two lists contained in a dossier seen by AAP.

The decision to spare the almost two dozen Nationals members from a more thorough investigation has been criticised by some within the party.

A well-connected party member and former Nationals employee said many of those cleared needed to be investigated further - including the alleged ringleader.

"Branch stacking is one thing, but these are actual Nazis," the party member told AAP.

"A lot of the names should be looked at more closely.

"How else do you find 20 other people who believe that kind of stuff unless you yourself believe that kind of stuff?"

The member suggested some of those on the "cleared list" were "teflon within the party ... they are protected".

A staff member for a NSW Nationals minister is also on the list of those cleared.

The dossier contains information about several party members and their links to the white supremacist or neo-Nazi movement, including screenshots of the alleged ringleader organising their memberships.

Other screenshots show members arguing the merits of fascism, or making coded references to Hitler and skinheads on social media.

The NSW Nationals temporarily suspended processing of new memberships in the Young Nationals when the revelations first surfaced earlier this month.

An ABC investigation uncovered the plot by the alt-right movement to join major political parties and influence their policies. It also found Young Nationals members were attending a secret men's-only fight club founded by prominent alt-right nationalists.

NSW Nationals leader John Barilaro has denounced racism and fascism within the party.

"I have no problems calling this out, this is something I'm very strong on, I do not accept racism," Mr Barilaro told the ABC in mid-October.

NSW Nationals Director Ross Caddell has been contacted for comment.