By Keith Coffman

DENVER (Reuters) - A candidate for a county commission seat in Colorado said on Friday he received a death threat after questioning whether the 2012 school shooting that killed 20 children in Connecticut was a hoax.

Thomas Ready, a Republican candidate for commissioner of Pueblo County, made the comments during a debate this week with his opponent, Democratic incumbent Sal Pace. A video of the exchange was posted online by the Pueblo Chieftain newspaper.

Twenty school children and six adults were killed in the Dec. 2012 shooting rampage at Sandy Hook Elementary School in Newtown, Connecticut.

The gunman, 20-year-old Adam Lanza, shot his mother to death at the home they shared before he went to his former school and opened fire. He committed suicide as police closed in.

During the debate, Pace said he was disturbed that Ready had posted on his Facebook page a link to a story that claimed the school shooting was a hoax perpetuated by the federal government to advance a gun-control agenda.

Ready responded by saying "there's still questions about whether it really happened," as audience members gasped.

"There was a picture of a man walking in whose daughter had died. He was smiling and joking," Ready said. "When he walked into the room, he turned and all of a sudden, had tears in his eyes. Why?"

Ready, a 70-year-old dentist who is making his first run for political office, told Reuters on Friday he received a death threat on Facebook from a man he didn't know.

He denied being a conspiracy theorist and said he often shares items online in order to provoke "open discussion."

"I know it (the massacre) happened," he said. "I have grandchildren of my own. It was a terrible, terrible tragedy."

His opponent Pace told Reuters that Ready's comments were "reprehensible and hurtful to the victims' families," but that the threat Ready received was likewise "inappropriate."

Rick Palacio, chairman of the Colorado Democratic Party, said in a statement that GOP leaders should denounce Ready's "irresponsible and asinine conspiratorial comments."

Ready, a one-time major in the U.S. Army, said that he did not report the death threat to police because he did not want to give the man who sent it notoriety.

(Reporting by Keith Coffman; Editing by Daniel Wallis and Sandra Maler)