"I have done nothing wrong," Manning said.
He added, "I have never done what I've been accused of doing."
Eric Inselberg, a sports memorabilia dealer, originally filed a civil lawsuit involving Manning and the Giants in 2014 claiming they forged game-used equipment. Jim Baumbach of Newsday noted in January 2016 a New Jersey judge ruled the case against the quarterback could proceed.
The allegations remained mostly dormant until last week when Kaja Whitehouse and Bruce Golding of the New York Post unearthed a potential "smoking-gun email" within the court documents.
Manning allegedly wrote a message to team equipment manager Joe Skiba in 2010 that read: "2 helmets that can pass as game used. That is it. Eli."
The lawsuit claims the email is evidence the quarterback attempted to falsify the nature of the equipment given to Steiner Sports as part of a memorabilia contract, according to the New York Post.
Court papers filed last year alleged the Giants went as far as giving longtime defensive end Michael Strahan a fake version of his Super Bowl XLII jersey after the game.
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