The lawsuit says Clash paid for a plane ticket from Florida to New York in 1996 and arranged for a car service to pick up the teen and bring him to his upscale apartment, where he gave him cash and showered him with "attention and affection" and ultimately engaged in numerous sexual acts.
Herman said he is poring over receipts and other documents to see if the car service was paid for by Clash's employers at Sesame Street.
Clash's attorney Michael Berger said in a statement that "the lawsuit is without merit and we will vigorously defend the case and Mr. Clash's reputation."
Sesame Street publicist Ellen Lewis said "we're confident in the actions that we took," but declined further comment, saying it was an issue between litigants.
Herman said the alleged victims didn't come forward sooner because they were afraid, but have found courage as others have spoken up.
He said they are compliant victims who participated in the sexual acts, but didn't consent because it's illegal for a minor to do so.
"Because they participated in the sex they feel like they're doing something wrong ... they're ashamed, they're embarrassed, not something they really want to talk about," he said.
Herman said he's been contacted by several other possible victims and is vetting their cases.