Page Six reports the picture in question was shot when the actor was filming Blood Diamond in 2006. The image features an inscription written by Mandela that reads: "To Leo DiCaprio, Best Wishes, Mandela, 4-8-07."
It is unclear why both DiCaprio didn't keep the picture at the time or how it made its way to memorabilia and autographs dealer, Moments in Time, years later. However, the company is now selling the snapshot for $25,000.
Upon learning the picture was for sale Tuesday, the Wolf of Wall Street star had his lawyer contact the memorabilia shop and ask for the photo back.
"The photo is clearly not their property," said an insider. "[DiCaprio] wants the picture. His lawyers are considering action."
Gary Zimet, owner of Moments in Time, told TMZ he purchased the photo last month and expects to sell it within days. He added he was "not concerned in the least" about the actor's legal actions.
"They think by trying to intimidate me that they can get the picture for free. The provenance is ironclad. Leo is welcome to buy it," Zimet said.