The man behind beloved character Elmo became embroiled in a sex scandal earlier this month (Nov12) after he was accused of having relations with a 16-year-old male seven years ago, when he was aged 45.
The allegations were subsequently recanted, but a second man, Cecil Singleton, claimed he had a sexual phone chat with the star in 1993 when he was only 15, and he sued Clash for $5 million (£3.1 million).
The double sex scandal prompted Clash, 52, to quit the show, and now a third man has accused the puppeteer of improper conduct.
In the papers, filed at a federal court in New York on Tuesday (27Nov12), the man - referred to as 'John' in the documents - claims Clash invited him to his apartment in the Big Apple after they had a phone chat line conversation, when the plaintiff was aged 16.
John, now 28, alleges Clash plied him with alcohol and ""groomed him"" before engaging in ""sexual contact"" that included oral sex.
He goes on to claim Clash stayed in touch with him after the encounter, although no further sexual contact occurred until he became an adult.
The documents state, ""As a 16 year old child, John was not emotionally or psychologically prepared for a sexual relationship with a grown man in his forties.""
John is seeking a trial and is suing for unspecified damages, according to TMZ.com.