Major League Baseball and the National Football League will investigate allegations in an Al Jazeera documentary that employees at an Indianapolis-based anti-aging clinic supplied performance-enhancing drugs to a host of professional athletes including quarterback Peyton Manning.

The report, which was to air Sunday night, used information it said was gathered by an undercover reporter who was actually a former athlete, Liam Collins, a British hurdler. It elicited denials from all corners — including from one of the primary sources.

Charlie Sly, who the report refers to as a pharmacist who worked with the Guyer Institute of Molecular Medicine in Indianapolis, makes claims to Collins in the documentary that he helped treat Manning after a neck injury in 2011. Collins secretly recorded his conversations with Sly, who also implicated Washington Nationals first baseman Ryan Zimmerman, Philadelphia Phillies first baseman Ryan Howard and NFL players Julius Peppers of Green Bay and James Harrison of Pittsburgh.

On Sunday, Sly posted a video on YouTube in which he recanted the information.

"The statements on any recordings or communications that Al Jazeera plans to air are absolutely false and incorrect," Sly said.

Dale Guyer, founder of the Guyer Institute, said Sly was an unpaid intern who worked for three months at the Indianapolis clinic, and not in 2011 but in 2013, after Manning had moved on from the Colts to the Denver Broncos.

Both the Colts and the Broncos made statements supporting Manning, and Manning was emotional during the pregame Sunday.

"It absolutely never happened," he said. "The whole thing is totally wrong."

NFL and MLB officials said such reports always lead to investigations.

Baseball

Dave Henderson dies suddenly

Dave Henderson, former major league outfielder who hit one of the most famous home runs in postseason history, died Sunday in Seattle after suffering a heart attack. He was 57.

Henderson, who had a kidney transplant in late October, was best known for his home run in the 1986 AL Championship Series for Boston. With the Red Sox one strike from elimination in Game 5, Henderson hit a two-run homer in the top of the ninth against the California Angels to send the series back to Boston. The Red Sox won Games 6 and 7 to advance to the World Series.

Henderson also played for Oakland, Seattle, Kansas City and San Francisco. He was an All-Star for Oakland in 1991.

Reds All-Star O'Toole dies

• Jim O'Toole, an All-Star pitcher for the Cincinnati Reds in the 1960s, died of cancer in Cincinnati. He was 78. O'Toole was the National League's starting pitcher in the 1963 All-Star Game.

• Joe Strauss, a sports columnist for the St. Louis Post-Dispatch who covered baseball for nearly three decades, died Sunday in St. Louis from complications related to leukemia. He was 54. He also wrote for the Baltimore Sun and Atlanta Journal-Constitution.

AROUND THE HORN

Junior hockey: Lukas Hrusik broke a tie 19 seconds into the third period and Slovakia beat Belarus 4-2 in its first Group B round-robin game in the world junior hockey championship in Helsinki. Denmark beat Switzerland 2-1 in Group A. The United States will face Sweden on Monday.

Skiing: Josef Ferstl, Germany's top downhill racer, is out for the season because of a knee injury suffered Sunday while training in Italy.

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