A furious Florida sports-memorabilia collector who shelled out $8,500 for an Eli Manning rookie helmet now fears that it’s a fake — and that he was played by the Giants superstar.

Kris Inchcombe said he bought the signed No. 10 helmet in 2006, around the same time that a new lawsuit claims the quarterback sent a bogus rookie-year helmet to market.

“Now I’m just questioning the authenticity,” Inchcombe, a St. Augustine, Fla., financial professional, said of the purported 2004 helmet.

“If somebody took my money and told me something that they portrayed to be one way and it wasn’t — that’s theft. That’s stealing.”

Inchcombe grew worried after seeing The Post’s report Thursday of a lawsuit by memorabilia collector Eric Inselberg.

Inselberg’s suit claims two-time Super Bowl MVP Manning and Giants officials have passed off “massive” quantities of bogus game-worn team memorabilia — and a 2004 rookie helmet was among the “forgeries.”

“Manning took the helmet, signed it, and placed it into the market, falsely claiming that it was a helmet used during his 2004 rookie season,” the suit states.

Manning dodged questions on whether he’d doctored helmets and jerseys, saying only, “The Giants told me this suit is completely without merit and I have no reason to believe otherwise.

“The Giants are going to fight it, and so will I.”

Inselberg’s lawsuit claims that the 2008 Manning Super Bowl helmet in the Pro Football Hall of Fame is also a fake — allegedly ordered up by Giants Vice President Pat Hanlon after he learned that Inselberg already owned the real deal.