(CNN) -- The puppeteer who gave Sesame Street's Elmo his voice allegedly threw a crystal meth sex party for a teenage boy in 2004, according to a federal lawsuit filed this week.
Sheldon Stephens, now 24, is the fourth man to sue Kevin Clash, but he was the first one to publicly claim he had a sexual relationship with him as a teen.
Stephens' lawsuit is "meritless and barred by the statute of limitations," Clash lawyer Michael Berger told CNN Tuesday. "Mr. Clash continues to deny any wrongdoing, and we intend to defend this case forcefully."
Although Stephens called it an "an adult consensual relationship" last November, the revelation triggered Clash's suspension from Sesame Street and eventually his resignation.
Clash, who provided the high-pitched voice of the iconic furry red Elmo since 1984, acknowledged a relationship between "two consenting adults" when Stephens' story first emerged, but he said it otherwise was a "false and defamatory allegation."
"I am a gay man," Clash, 52, said in a statement in November. "I have never been ashamed of this or tried to hide it, but felt it was a personal and private matter."
Three other men soon emerged with federal lawsuits, filed last November and December, accusing Clash of befriending them as teenager then engaging in sex with them. They are all represented by Florida lawyer Jeff Herman, who also filed Stephens' lawsuit Monday.
Clash's lawyer has asked a judge to dismiss the three other suits based on his argument that the men waited too long to sue. The federal statute of limitations on such civil cases is six years, while their allegations involve relationships that ended more than 10 years ago, Berger said in a court filing this month.
Each lawsuit contends that the men only realized in the last year or so that they suffered psychological and emotional damage from their encounters with Clash.
"Clash was an adult male living a prominent public life centered around the entertainment of toddlers, while at the same time he was, in secret, preying on teenage boys to satisfy his depraved sexual interests," the Stephens suit alleged.
While the allegations in the newest suit mirror what the other men contend, Stephens' complaint is the only one to allege drug use by Clash.
"Clash smoked crystal meth while engaging in sexual activity with Sheldon," the lawsuit said. "Clash also gave Sheldon 'poppers' as a sexual aide. While Clash had sexual contact with Sheldon, the chauffeur watched and masturbated." "Poppers" generally refers to alkyl nitrites in capsule form that produce a physical rush when broken and inhaled: crystal meth refers to crystal methamphetamine.
Stephens was 16 when he met Clash in New York "at a social networking event for models and actors," the suit said.
"Clash told Sheldon he would help Sheldon with his acting career," it said.
Clash resigned from his job on "Sesame Street" after the first lawsuit was filed in November.
"I am resigning from Sesame Workshop with a very heavy heart," Clash said in a written statement at the time. "I have loved every day of my 28 years working for this exceptional organization. Personal matters have diverted attention away from the important work Sesame Street is doing and I cannot allow it to go on any longer. I am deeply sorry to be leaving and am looking forward to resolving these personal matters privately."
Despite his stepping down, Clash's voice will be used for Elmo through 2014, as the next season of "Sesame Street" has already been filmed.
CNN's Carolyn Sung contributed to this report.