"We have to be very protective," Lehmkuhl tells the TV show "Inside Edition" in an interview that was to air Wednesday.
"I am not going to hide," says the former Air Force captain and winner of season four of CBS' "Amazing Race." "There are threats that come in from people who do not want me to be so public and expose what is going on in the military."
Lehmkuhl, 32, says that he and Bass, who revealed he is gay in July, forward the threats to private security personnel who send what they consider the more serious ones to the FBI. "Everything is being covered so we feel safe," he said.
Lehmkuhl's book, "Here's What We'll Say: Growing Up, Coming Out, and the U.S. Air Force Academy," recounts his time keeping his sexual orientation a secret from Air Force colleagues.
"There was definitely an institionalized acceptance of people being homophobic and telling gay jokes and making homophobic remarks — really, really mean homophobic remarks to the point of, 'Kill gay people,'" Lehmkuhl, who was honorably discharged from the Air Force five years ago, told ABC News earlier this week.
He became a target when people began to suspect his sexuality, he says. One night, he told ABC News, a bag was pulled over his head and he was sexually assaulted. He didn't report the incident.