Brad Trost's campaign says it is has been put "on notice" by the Conservative Party for illicitly leaking a party membership list to a gun owners' rights group, CBC News has learned.

However Trost's campaign manager said he can find no proof the leak came from the Saskatchewan MP's camp.

"What we have is an allegation. We've seen no evidence," said campaign manager Joseph Ben-Ami.

When the party handed out copies of the membership list to the leadership campaigns, it engaged in a process called "salting," meaning each campaign received a slightly different copy to allow the party to trace potential leaks.

Ben-Ami said the party reached out to the Trost campaign last Saturday to say it believed it was their version of the list that was given to the National Firearms Association, an Edmonton-based organization that advocates for gun owner and property rights.

Since then, Ben-Ami said all six members of the Trost campaign who had access to the data have been interviewed and the campaign's data logs and security arrangements have been checked. Those checks turned up nothing, he said.

"It would be wrong to say we pushed back [against the party]. We simply wrote back to the party and said there's no indication that any list originated with us. So we've asked them to provide us with whatever information or evidence in their possession to indicate that the list was in fact our list," he said.

Ben-Ami noted that Trost, who ran a campaign based on social conservative values and came in fourth, did not personally have access to the list. However, he said others beyond the Trost campaign did have access to the very same copy.

"The party people themselves had access to the data."

Cease and desist

Last week, the party announced on Facebook that it had received complaints an outside organization was reaching out to its members. On Monday, the party's lawyer sent a cease and desist letter to the National Firearms Association.

The party is demanding the NFA return any hard copies of the membership list and delete any electronic copies. It also wants the party and the Conservative Fund to have access to the NFA's electronic database to be sure all the membership information has been permanently deleted.

​​"Having a third party have access to our party membership​ list is just something that's not acceptable," Dan Nowlan, chair of the party's leadership election organizing committee, told CBC News earlier this week.

The NFA has not responded to a request for comment from CBC News.

In its assessment of each candidate's firearms' policies, the NFA gave Trost a "B." Only three candidates got a higher grade. However, Ben-Ami said his campaign had no connection with the group.

"We have no relationship with the National Firearms Association. Period. Full stop," said Ben-Ami.

Sorting out consequences

The Conservative party's chief returning officer was charged with looking into allegations surrounding the NFA's acquisition of the list.

Once that investigation is finished, the party must decide on any disciplinary measures. A spokesman from the Conservative Party of Canada said no decision has yet been made on how to deal with the situation.

One option would be to a fine. Each candidate had to give the party a $50,000 compliance deposit by Jan. 1, which was refundable if the candidate followed the rules.

The sums still haven't been returned and could be docked if campaigns were found to have engaged in bad behaviour during the race.

Ben-Ami said he's still waiting for the party to provide him with more information. He said it would be "very disappointing" if the party moved ahead without providing that information.

"I don't think that's proper due process."