Photographer Steve Eichner — whose new book, “In the Limelight: The Visual Ecstasy of NYC Nightlife in the ’90s,” chronicles the 1990s club scene in pictures — told us that DiCaprio made a deal with him one night in 1994 at Club USA during a party for the Nicolas Cage-Dennis Hopper thriller “Red Rock West.”

At Peter Gatien’s legendary club venue, Eichner said he got a shot of Leo — who would have been about 20 at the time and had just starred in his dramatic movie breakout, “What’s Eating Gilbert Grape,” with Johnny Depp — buying something from a “cigarette-and-candy girl,” but he couldn’t tell what. “[Leo] came over and tapped me on the shoulder and said, ‘Hey man, can you do me a favor and please don’t use that photo? You can take photos of me tonight.’ ”

When asked why he didn’t want the picture to go public, Eichner recalled that Leo told him, “I was buying cigarettes, and I don’t want my mom to know that I smoke.”

DiCaprio is famously close with his mother, Irmelin Indenbirken.

Oddly enough, Depp corroborated Eichner’s claim that DiCaprio kept his smoking habit from his mom.

In 2016, at the Santa Barbara International Film Festival, Depp told an anecdote about a young co-star pestering him on the set of “What’s Eating Gilbert Grape.” “No, I will not give you a drag of my cigarette while you hide from your mother again, Leo,” Depp recalled himself saying to the rising star.

Some (perhaps apocryphal) reports from many years ago have also said that DiCaprio helped Robert Pattinson quit smoking by turning him onto e-cigarettes. Eichner’s book comes out Oct. 20 from Prestel.