Quarterback Eli Manning and New York Giants brass created bogus “game-worn” football gear to pass off as the real deal — and one of the forgeries is sitting in the Pro Football Hall of Fame, an explosive new lawsuit claims.

A helmet on display in the hallowed Canton, Ohio, gridiron museum — supposedly worn by Manning in Big Blue’s 2008 Super Bowl victory over the New England Patriots — is just one of dozens of fake items the football superstar and his Giants cohorts have created to fool fans and make money from collectors over the years, the lawsuit alleges.

Other “forgeries” passed off on collectors include several Manning jerseys, two 2012 Super Bowl helmets and a 2004 “rookie season” helmet, according to court papers.

Two-time Super Bowl MVP Manning took part in the scheme so he could hang on to his personal items, according to the documents.

The memorabilia ruse is so common among Giants players and staffers, the documents claim, that team equipment manager Joe Skiba openly discussed Manning’s fake game gear on an official Giants e-mail account.

The lawsuit emerged as Manning’s big brother, Peyton, prepares to lead the Denver Broncos against the Seattle Seahawks in Sunday’s Super Bowl at MetLife Stadium, the Giants’ home field.

The allegations are part of a civil-racketeering, breach-of-contract, malicious-prosecution and trade-libel suit filed Wednesday in Bergen County Superior Court by sports collector Eric Inselberg.

In one startling claim, the suit says Barry Barone, who has been the Giants’ dry cleaner since 1982, used his Rutherford, NJ, Park Cleaners store to beat up jerseys and other items at the behest of longtime locker-room manager Ed Wagner Jr.

In a 2001 incident, Wagner told Barone “to intentionally damage multiple jerseys to make them appear to have been game-worn when they had not been.”

Inselberg’s lawyer, Brian Brook of Clinton Brook & Peed, said his client walked in to find Barone “using a big pair of scissors to cut up a set of Giants’ 2000 season’s game-issued white jerseys,’’ in order to then “’repair’ those damages” to make the shirts look used.

Inselberg was indicted in 2011 for memorabilia fraud for selling bogus used sport jerseys from teams.