The political network largely funded by billionaire industrialist Charles Koch has been quietly touting North Carolina Lt. Gov. Mark Robinson for his policy positions despite a litany of controversies, according to records uncovered by CNBC.

The Koch-backed Americans for Prosperity ran digital advertisements supporting Robinson as recently as this month. It's also funded pro-Robinson door knocking, launched a website that encouraged voters to thank him for his work as lieutenant governor, interviewed him on a podcast and hosted him for an April event featuring Sen. Ted Budd, R-N.C.

The digital ads began running Sept. 1 and continued to air through Sept. 14, according to AdImpact. The ads aired just days before CNN reported on racist and graphic comments Robinson allegedly posted on a porn forum over a decade ago.

Though Robinson has denied he wrote the scores of posts, at least four of his top aides from his North Carolina gubernatorial campaign resigned within days of the report's publication. The National Review reported a total of eight staffers have resigned.

The September pro-Robinson ads funded by AFP feature a message of praise for the lieutenant governor's advocacy to expand the state's school voucher program, as well as a testimonial from Robinson himself. These types of voucher programs use taxpayer funds typically spent on public education to subsidize private school tuitions.

"Now today, thanks to lieutenant governor Robinson and leadership in the North Carolina general assembly, families across the state have access to the school that best fits their child's needs," a voiceover for the AFP ads says.

AFP says the "thank you" ads are not the same as an endorsement, but merely intended to reward elected officials who back policies the nonprofit supports.

That said, during an election year any positive ads will have the effect of boosting the candidate's campaign, whether this is deliberate or not.

"We have not engaged in this race or endorsed Mark Robinson, but we routinely thank public officials when they do the right thing on policy — especially when it comes to an issue as important as education freedom," AFP's spokesman told CNBC.

As of Monday, Robinson had refused to withdraw from the governors' race, where he is trailing Democrat Josh Stein by an average of 9.5 percentage points, according to a Real Clear Politics average.

The Republican Governors Association said Monday that it has no plans to make further ad buys on Robinson's behalf in the state.

Americans for Prosperity ran supportive ads after many of Robinson's controversial comments. In February, for instance, Robinson suggested that transgender women should be arrested if they used women's bathrooms.

The move by Americans for Prosperity, or AFP, to back Robinson from a policy perspective surprised some North Carolina Republican strategists.

"We've seen for months this wasn't going to be a close race, even before Labor Day," said Jonathan Bridges, a state Republican strategist who previously worked for Robinson's primary rival, former Rep. Mark Walker, R-N.C. "Why would they still do anything after Labor Day? If I was in that position, I probably wouldn't do that."

AFP's effort to support Robinson represents a shift for the group, after the organization's state office opted out of backing him during his initial run for lieutenant governor in 2018, according to Chris McCoy, who served as AFP's North Carolina state director until 2022.

"They were superficial conversations and nothing deep," McCoy said in describing the deliberations at AFP's state level on whether it should back Robinson. "The concept was going to be dead before it got off the ground. I wouldn't have even tried. Robinson is a polarizing character."

Fast forward six years, however, and Robinson won the Republican gubernatorial primary in March, boosted by an endorsement from former President Donald Trump.

Since then, AFP has been knocking on doors with a thank you message tied to Robinson's policy positions as lieutenant governor, a spokesman confirmed, adding that the group does not consider this work tantamount to an endorsement.

The majority of the door knocking was spent thanking other members of the state legislature besides Robinson, the spokesman said.

AFP also encourages those visiting its website to sign a letter thanking Robinson "for leading on the issues that matter in North Carolina."

AFP's support for Robinson didn't stop with the two digital ads and a website.

The group hosted Robinson, Budd and other state officials in Greensboro, North Carolina, in April to take aim at President Joe Biden's economic policies, according to social media posts about the event.

AFP also hosted Robinson on its podcast "American Potential" months after he first announced his campaign for governor.