Why Leonardo DiCaprio Didn't Attend 'Titanic 3D' Premiere

Kevin Winter/Getty Images for AFI

The actor was in Louisiana shooting "Django Unchained," a source tells THR.

When Titanic 3D premiered in London on Tuesday, one of the epic blockbuster's biggest stars was conspicuously absent. Kate Winslet was there. So was James Cameron, who had just surfaced from a historic dive of almost 36,000 feet to the bottom of the Pacific Ocean's Mariana Trench.

But no Leonardo DiCaprio?

According to a source close to the actor, DiCaprio could not attend the premiere because he's been in Lousiana filming Quentin Tarantino's Django Unchained.

GALLERY: 'Titanic 3D' London Premiere

The film, set in the 1800s, also stars Jamie Foxx, Joseph Gordon-Levitt and Christopher Waltz. DiCaprio portrays a plantation owner named Calvin Candie who keeps the main character, Django (Foxx), as a slave; Waltz is the German bounty hunter who helps him scour the American South in search of his wife.

As that movie continues production, DiCaprio's breakout film is being re-released in 3D. The star, 37, was just a kid when he tugged at the world's heartstrings as Titanic's poor yet idealistic hero Jack to Winslet's rich girl Rose; the 1997 romantic adventure grossed $1.84 billion worldwide -- the second-biggest film of all time behind Cameron's Avatar -- and also was critical success, winning 11 Oscars including best picture and director.