FILE PHOTO: Colin Kaepernick puts his hand over his heart in response to a comment at a special training event created by Kaepernick to provide greater access to scouts, the media, and the public, at Charles. R. Drew High School in Riverdale, Georgia, U.S., November 16, 2019. REUTERS/Elijah Nouvelage/File Photo

By Rory Carroll and Lisa Richwine

BEVERLY HILLS, California (Reuters) -Director Spike Lee's multi-part documentary series for ESPN Films about former NFL quarterback Colin Kaepernick, who sparked a national debate when he protested racial injustice nearly a decade ago, will not be released, the filmmaker and ESPN said.

"ESPN, Colin Kaepernick and Spike Lee have collectively decided to no longer proceed with this project as a result of certain creative differences," ESPN said in a statement to Reuters on Saturday.

"Despite not reaching finality, we appreciate all the hard work and collaboration that went into this film."

Lee told Reuters on Friday that the series was not going to be released.

"It's not coming out. That's all I can say," Lee said on the red carpet ahead of the Harold and Carole Pump Foundation dinner, a fundraiser for cancer research and treatment, in Beverly Hills, California.

Asked why, the Oscar-winning director declined to elaborate, citing a nondisclosure agreement.

"I can't. I signed a nondisclosure. I can't talk about it."

Kaepernick played for the San Francisco 49ers from 2011 to 2016. He ignited a national debate in 2016 when he knelt during the U.S. national anthem to protest systemic racism and police brutality.

The 37-year-old athlete has not played in the NFL since that season. Many experts believed his political activism, which triggered a movement that drew the ire of U.S. President Donald Trump, was the key reason teams were wary of signing him.

He later filed a collusion grievance against team owners, which was settled with the league in 2019.

A representative for Kaepernick said the player had no comment about the docuseries on Saturday.

Production on the series began in 2022, with Walt Disney-owned ESPN touting it as a "full, first-person account" of Kaepernick's journey that would feature extensive interviews with the player.

In September, Puck News reported the project faced delays amid disagreements between Kaepernick and Lee over the direction of the film, and that ESPN Chairman Jimmy Pitaro was open to allowing the filmmakers to shop it elsewhere.

(Reporting by Rory Carroll and Lisa Richwine in Los Angeles; Editing by Matthew Lewis)