(CNN) Interior Secretary Ryan Zinke put a right-wing commentator who has promoted numerous conspiracy theories on the board of his super PAC in 2012.

The move was part of Zinke's longtime association with retired Maj. Gen. Paul Vallely, a promoter of the birther conspiracy theory, which falsely alleges former President Barack Obama is not a natural born US citizen. In 2010, Vallely said that he firmly believed Obama "is a Muslim in nature" and said there was "no proof that I've seen that he was born in Honolulu."

CNN's KFile previously reported on Vallely's appearance on Zinke's radio show in April 2013, when he brought up a false conspiracy theory that a Saudi national was involved in the Boston Marathon bombing. In that appearance, Zinke called Vallely a "great patriot."

A CNN KFile review of Zinke's interaction with Vallely reveals their relationship went far beyond the radio show appearance.

When Zinke launched his veterans-oriented, anti-Obama super PAC Special Operations for America in July 2012, Vallely was quoted in the press release and was listed as one of six members of the board.

Zinke's super PAC also linked to an article by Vallely in which he wrote that a "civil uprising" was not "out of the question" to stop Obama who was facilitating the rise of "radical Islam, the caliphate, and Jihad -- the slow infiltration and dismantling of our American institutions" either "willfully, or due to sheer naiveté." On the group's website, the article is described as "outstanding."

Asked about Zinke's relationship with Vallely, Interior Department press secretary Heather Swift said in a statement, "Ryan Zinke is a retired Navy SEAL commander who respects the general's service and respects the sacrifice of the Vallely family who lost their son while he was serving in the Army."

In an interview with CNN's KFile, Vallely said he has known Zinke for more than 10 years, adding that they talked about issues from their shared military perspective. Vallely has endorsed Zinke several times in his runs for political office and has attended events and private dinners with him as recently as 2017. Vallely calls Zinke a friend and the pair are friends on Facebook

"I always admired his military performance, his honesty, and then he ran, started running for political office — I can't remember the year — and I attended a number of events in support of Ryan and I've been a close friend ever since and I'm very happy that he's doing well in the administration," Vallely said.

Asked whether the two had ever discussed his controversial views, such as his skepticism that Obama was born in Hawaii and his suspicion that the former president was a Muslim, outside of the radio interview, Vallely told CNN's KFile, "I don't remember. We may have," before disputing the notion that he was a "birther."

"I just questioned, along with others, where he was born. That doesn't make me a birther," Vallely said.