On eve of major film about her life, swimmer Diana Nyad's past is questioned again

"Nyad," a major motion picture about Diana Nyad, who swam from Havana to Key West at age 64 in 2013, is being marketed as a "remarkable true story of tenacity, friendship, and the triumph of the human spirit."

Why it matters: Nyad grew up in Fort Lauderdale. The film, poised to debut at the Telluride Film Festival this weekend before showing in theaters and on Netflix, is putting her controversial career back in the spotlight.

• Nyad's famous swim led to her being cast on "Dancing With the Stars," getting a book deal and becoming a motivational speaker. She has published numerous op-eds in the New York Times and Washington Post.
• But marathon swimmers have questioned Nyad's truthfulness over the course of her career, and some still question aspects of the Cuba swim that made her famous.

Yes, but: Director Jimmy Chin told Vanity Fair earlier in August, "As documentary filmmakers, the first thing we did was to look into some of these criticisms — and found that they weren't valid."

Catch up quick: Nyad made headlines in the 1970s for swimming around Manhattan and attempting a Cuba to Florida swim. She finally achieved it on her fifth attempt in 2013.

• Critics raised suspicions about it afterward, alleging that protocols for epic swims were not followed. She'd been touched by her crew and the feat was not filmed from start to finish by independent media.
• They questioned whether it qualified as "unassisted," as Nyad had claimed, because of a special suit and mask she'd used and lotions she applied.
• Nyad defended herself, calling the criticisms "outrageously petty."

Between the lines: Retired marathon swimmer Daniel Slosberg has for years compiled video and newspaper clips on the website NyadFactCheck.com, purporting to show that Nyad has made exaggerations, fabrications and contradictions about topics such as her pacing and records.

• "She's being celebrated, and she's been lying for 50 years straight," Slosberg tells Axios.
• Slosberg claims other accomplished swimmers have been unfairly overshadowed by Nyad.
• Nyad did not directly respond to Slosberg's accusations, but told the Los Angeles Times this week, "Am I embarrassed to have inflated my own record when my record is pretty good on its own? Yes, it makes me cringe."

State of play: A consultant who founded the World Open Water Swimming Association (WOWSA), one of the sport's two global organizations, had lent credibility to Nyad's Cuba swim.

• WOWSA completed an exhaustive review of Nyad's Cuba swim last year and subsequently parted ways with the consultant.
• In that review, WOWSA made clear it had found no evidence that Nyad "exited the water or gained forward momentum from a support vessel or other object or person during the swim."
• Although GPS data showed her speeding up at one point, WOWSA raised objections for myriad other reasons and said in a statement this August that "a significant gap in the records, particularly during a period when Nyad's condition shifted dramatically, calls for further expert analysis."

What we're watching: WOWSA wrote in the announcement that in light of its findings, the Guinness Book of World Records revoked its recognition of Nyad's swim as record-breaking.

• WOWSA said in its statement that Nyad's memoir, on which the film is based, was not "rigorously fact-checked," and that it advised Netflix "to include a disclaimer emphasizing the film's dramatized nature."

Of note: Some marathon swimmers have lauded Nyad's achievements as a distance swimmer regardless of the particulars, and suggested that ageism, sexism and homophobia have played into criticism of her.

• Nyad, her coach, Chin and Netflix all did not respond to requests for comment from Axios.
• Supporters continued to defend her and emphasize there was no evidence she'd cheated during the Cuba swim.
• Evan Morrison, co-founder of the Marathon Swimmers Federation, said, "Her increase in speed in the middle of the strait is explained by a gyre in the Gulf Stream." He shared an open letter he'd written to the marathon swimming community regarding the movie.
• Steven Munatones, the consultant who'd founded WOWSA, rejected criticisms and told Axios, "The key point is that this 64-year-old woman did this incredible feat."

Editor's note: This story has been corrected to reflect that WOWSA's founder, Steven Munatones, was affiliated with the organization when it undertook its review of Nyad's 2013 swim, and to clarify why and when WOWSA called for further expert analysis of the swim. Earlier, the story was updated with comments from Evan Morrison of the Marathon Swimmers Federation and Munatones.