It’s not a sunny day on “Sesame Street,” as the show revealed Monday that the puppeteer behind Elmo has been accused of having a sexual relationship with an underage boy. Kevin Clash, the voice of the famous Sesame Street puppet, has taken a leave of absence after a man said he had an ongoing sexual relationship with Clash when he was 16 and Clash was 45.

Clash, 52, who has been Elmo’s Muppeteer since 1984, adamantly maintains the accusation is false, but the show was forced to investigate.

Says Clash, according to TMZ, “I had a relationship with [the accuser].  It was between two consenting adults and I am deeply saddened that he is trying to make it into something it was not.”

Sesame Street has since released a statement saying in part: “In June of this year, Sesame Workshop received a communication from a young man who alleged that he had a relationship with Kevin Clash beginning when he was 16-years old.  This was a personal relationship, unrelated to the workplace.  We took the allegation very seriously and took immediate action.”

“We took the allegation very seriously and took immediate action,” Sesame Workshop said in the statement. “We met with the accuser twice and had repeated communications with him. We met with Kevin, who denied the accusation. We also conducted a thorough investigation and found the allegation of underage conduct to be unsubstantiated.”

While the show’s probe was unable to find proof that Clash had engaged in a relationship with the accuser while he was a minor, it did find evidence that the man behind one of the most beloved children’s television characters had engaged in inappropriate behavior against company standards.

“Although this was a personal relationship unrelated to the workplace, our investigation did reveal that Kevin exercised poor judgment and violated company policy regarding internet usage and he was disciplined,” Sesame Workshop said.

In light of the incident, Clash will be moving away from Sesame Street for the foreseeable future.

“Kevin insists that the allegation of underage conduct is false and defamatory and he is taking actions to protect his reputation,” the Workshop noted. “We have granted him a leave of absence to do so.”