The Bears and former linebacker Brian Urlacher denied any involvement Wednesday with the Ruth Institute -- an affiliate of the National Organization For Marriage, which opposes same-sex marriage -- after an online promotion for the institute stated a clear involvement of the team.

The Ruth Institute, aimed toward young adults and students, promotes marriage between a man and woman and is opposed to same-sex marriage, according to its website.

In an advertisement for its June gala at an upcoming conference, the California-based group stated, "For now, you should know that we have two fabulous raffle items from the Chicago Bears Organization (and a huge THANK YOU to the Bears for supporting our message)."

Below the statement are images of an autographed Urlacher jersey and an autographed black-and-white photo of deceased Hall of Fame running back Walter Payton.

"I sign a lot of stuff for charity and I don't always know where it goes," Urlacher told the Tribune. "If I would have known it was for this cause, I wouldn't have done it."

Payton's older brother Eddie Payton said he did not know of any memorabilia regarding his brother used to support an anti-gay marriage group.

"This is the first I've heard of it," said Payton, a former NFL kick returner. "Walter treated everybody equal. Ã‚â€¦ Only Walter could speak for himself, but it's a touchy subject. It should be a non-subject."

The Bears issued a statement, saying "The two items featured in The Ruth Institute gala invitation were personal donations to (President) Dr. Jennifer Roback Morse. Neither was a club donation, nor do they represent the team's view on any social issues. Any remarks stating otherwise are false."

Reached by phone Wednesday afternoon, Morse initially declined comment. But her website later dropped all references to the Bears at the team's request, and Morse issued a statement: "The Ruth Institute is not working with the Chicago Bears organization or any of its players past or present to promote our upcoming auction. The memorabilia we are auctioning off was acquired by me personally, not through the team or players. We understand that the Chicago Bears organization takes no position on social issues, and we regret any confusion we may have caused on this point."

Morse declined to disclose where she acquired the items. Memorabilia, including that certified as authentic, is readily available online. She also did not explain why her site thanked the team for its support if it was not working with the institute. NOM was founded in 2007 and is a well-known nonprofit in the fight against same-sex marriage. The Ruth Institute was founded later by Morse, currently a senior research fellow at the Acton Institute.

The matter first was raised by the website Equality Matters, a gay rights initiative from the liberal Media Matters website. Equality Matters published an article last year that alleged the Ruth Institute provided anti-gay materials to its conference attendees.

Tribune reporters Vaughn McClure and Fred Mitchell contributed. jahopkins@tribune.com Twitter: @jaredshopkins