Bennet Omalu and Will Smith attend the “Concussion” cast photo call at Crosby Street Hotel on Dec. 14, 2015 in NYC. (Photo by Grant Lamos IV/Getty Images)

The release of Will Smith’s upcoming movie, “Concussion,” has been clouded by claims from the scientific community that Smith’s character, the real-life Bennet Omalu, has exaggerated his contributions to the study of a brain disorder affecting professional football players.

These assertions have jarred an otherwise uplifting story about an immigrant’s fight to save some of America’s most revered athletes.

In 2002, famed Pittsburgh Steelers center Mike Webster died at just 50 years of age, after suffering from dementia and other mental ailments that seemed to come out of nowhere.

The sudden demise of the former NFL star, who was known on the field as “Iron Mike,”was mourned by football fans all over the country, and nowhere more than in Pittsburgh, the Steel City where he made his name. Everyone wondered what could have caused Webster’s health to so drastically deteriorate and trigger what was initially reported as a heart attack that ended his life.

Three years later, a young Nigerian immigrant doctor offered the answer.

Omalu, then a researcher at the University of Pittsburgh’s pathology department, conducted an autopsy on Webster that determined it wasn’t a heart attack that killed the football player, but rather a neurodegenerative disease called chronic traumatic encephalopathy (CTE).

The disease, found in people with a history of repetitive brain trauma, causes brain degeneration that can lead to memory loss, confusion, impaired judgment, impulse control problems, aggression, depression and progressive dementia years or even decades after the last brain trauma.

In his waning years, Webster was separated from his family, reportedly heavily in debt and suffering from depression and memory loss.

The publication of Omalu’s findings in Neurosurgery journal in 2005 was followed by a classic David and Goliath struggle: The NFL tried to discredit Omalu’s work, calling on him to retract his original article, even as a growing chorus of other neuroscientists chimed in to support his claims.

This tale ripe for Hollywood will be appearing on the big screen Christmas Day, with Smith portraying a valiant Omalu who stands up for his research in the face of an NFL trying to intimidate him into silence. (“I think you’re going to be an American hero,” one character tells Omalu in the movie trailer.)

If the trailer is any indication, Omalu is also recognized as the first scientist to discover CTE. “I found a disease that no one has ever seen,” Smith’s character says.

But scientists told the Associated Press that Omalu neither discovered the disease nor named it, though his research was essential to directing attention to the impact of CTE on football players. They said taking credit for unearthing the disorder altogether, however, goes one step too far.

“Chronic traumatic encephalopathy has been around for decades,” William Stewart, a neuropathologist at Queen Elizabeth University Hospital in Scotland told the AP. “The only thing I would say that Bennet has done is that he identified it in an American footballer.”

Of the assertion that the first knowledge of CTE came from Omalu, Stewart said, “It’s just not true, and I think he knows that.”

Speaking over the phone to The Washington Post on Sunday evening, Omalu declined to comment, saying simply, “It’s not worthy of a response.”

He previously told the AP that the criticisms came from “people historically who have made a systematic attempt to discredit me, and to marginalize me…. There is a good deal of jealousy and envy in my field. For me to come out and discover the paradigm shift, it upset some people. I am well aware of that.”

Or, as a doctor played by Alec Baldwin in the film said of Omalu’s contributions: “You turned on the lights and gave [the NFL’s] biggest bogeyman a name.”

Except the term “chronic traumatic encephalopathy” had already been used to describe the disorder as early as 1949, when British neurologist MacDonald Critchley wrote a paper about the disease’s prevalence among boxers.

Sony Pictures, the movie’s production company, said in a statement last week that “competing interests and agendas” explain the attempt by some to “undermine” Omalu’s work.

It is common for movies to dramatically venerate or vilify real people, and audiences have come to expect this. The “based on a true story” tag on films such as “Concussion” is generally taken with a large grain of salt, if not a very liberal understanding of the word “based.”

But in this case, Hollywood drama isn’t entirely to blame: Omalu has himself suggested that he both discovered CTE and coined its name.

“I said to myself, Bennet, you cannot just publish this as another disease — it will be drowned,” Omalu said in a lecture in 2013. “You need to give it a name, and you need to give it a sexy name. You need to give it a name that has a good acronym that people would remember — even the 3-year-old kid would remember. That was how CTE came about.”

Speaking with the AP, Omalu softened his take, saying, “The pathology of CTE in a football player had not been known before I described this disease.” But he was responsible for making CTE “a proper noun,” he said.

Arthur Caplan, the director of medical ethics at NYU’s school of medicine, told the AP that publicly failing to acknowledge the work of previous researchers “would be unethical” and “certainly un-collegial.”

Smith did not address the underlying history of CTE research during an interview with CNN last Friday. On the contrary, the actor credited Omalu with inspiring him to take the role.

“After I met Dr. Omalu and I sort of understood the science behind it, as a parent I felt compelled to tell this story,” said Smith, whose older son, Trey, was a high school football star.

The official trailer for “Concussion” closes with a scene showing a passionate Omalu saying, through gritted teeth: “Tell the truth. Tell the truth!”

More from Morning Mix

When your 4-letter brand becomes a 4-letter word: How ISIS became Ionis

Steve Harvey crowns wrong Miss Universe