Leonardo DiCaprio is here one moment, gone the next. For a while, he is photographed everywhere. He is quoted endlessly. And then, his image and words are nowhere to be found. Is it a coincidence?

The truth is that the popular actor sees himself as an escape artist, performing a disappearing act whenever he has nothing to sell.

“It is very conscious on my part,” he explains in the quiet comfort of a plush Beverly Hills hotel suite.

“There is a certain amount of publicity you need to have, but then there is only so much the public can take of someone. Even I get sick of myself sometimes. After ‘Titanic,’ I couldn’t stand to look at my own face anymore.

“So, when I’m not trying to sell a movie or get publicity for a charity, I try my best to disappear. I stay away from paparazzi hot zones, and I don’t do unnecessary interviews or get photographed if I can help it.”

Well, DiCaprio is visible again, this time to promote “Blood Diamond,” which opened this weekend. It is one of two recent movies — the other being Martin Scorsese’s “The Departed” — that have put DiCaprio in the frontrunner spot for a best-actor Oscar.

In “Blood Diamond,” he plays a tough, greedy and always charming Zimbabwean smuggler who teams with a reluctant partner in war-torn Sierra Leone to retrieve a large diamond. He wants the treasure for monetary gains, but his partner (a local played by Djimon Hounsou) wants to use the gem to pay ransom for his young son, who has been caught up in the civil war that engulfed that West African nation in the 1990s.

Blood diamonds, also known as conflict diamonds, refer to gems that are smuggled out of a country to pay for weapons to continue the war within that country.

The diamond industry mounted an elaborate campaign in advance of the movie’s release to counter the negative image it expects, but DiCaprio and director Ed Zwick insist they are not indicting the entire industry.

“We’re not asking consumers not to buy diamonds,” DiCaprio said. “We’re asking them to use their best judgment when they do buy diamonds. Ask the right questions. Ask for documents to prove that what you’re buying are not conflict diamonds.”

DiCaprio, 32, acknowledged that the chance to spread an important message was one of the factors that led him to take the role. But it wasn’t the only factor.

“I wasn’t seeking out a script with a political message,” he said. “There has to be entertainment value. Without that, the message comes off like preaching. This movie is more than a message movie. It’s an entertaining action movie that happens to have a message.”

DiCaprio said he immersed himself in the role, researching the part through written material and studying the dialects and mannerisms of South African mercenaries.

“To watch Leo work,” director Zwick said, “is to watch one of the truly great actors in Hollywood.’’

“Like Denzel,” says Zwick, who directed Denzel Washington to his first Oscar-winning performance in the 1989 Civil War drama “Glory,” “Leo utterly inhabits his space on the screen. His process of immersion in the character, from the jargon to the mannerisms, is complete.

“He also reminds me of such great actors as Henry Fonda, Kirk Douglas and Burt Lancaster, who were not afraid to play rough characters that their audiences had never seen before. Most actors don’t have the courage to do that, but Leo is not afraid. He could easily play it safe and remain at the top for the next 20 years, but he is willing to challenge himself and his audience by digging into more complex and ambiguous characters.

“He is not content with being Leonardo DiCaprio, the movie star. He’s wants to be Leonardo DiCaprio, the actor. And, if that wasn’t impressive enough, he’s a great guy.”

HOME-COURT ADVANTAGE

DiCaprio is the first to admit that if he hadn’t grown up in Los Angeles, he never would have become an actor.

His older stepbrother had an agent and was appearing in commercials and TV spots. DiCaprio thought it might be fun and got his own agent at 9.

Unfortunately, he was wearing his hair in a Mohawk at the time, and he couldn’t find work. Three years later, he had a new haircut, and he got a role on the short-lived TV series “Parenthood.” A year on the popular series “Growing Pains” followed.

“Listen, I had no show business ambitions in the beginning,” the actor said. “I was having fun impersonating all my mom’s friends and being the class clown at school. That was good enough for me. But my brother seemed to enjoy it, and it looked easy because we lived in L.A. I figured I’d do it part-time and then go back to school.”

In 1991, he was cast in his first movie role in the forgettable “Critters 3.” His first significant movie role was opposite Robert De Niro two years later in “This Boy’s Life.”

“Even when I was working on the TV series, I never even thought about being in movies. When this audition came up, I wasn’t really familiar with De Niro’s work, and I didn’t know enough about his standing in the film industry to be nervous. I should have been but I wasn’t, and that gave me an advantage. Everybody else at the audition was terrified.

“After I got the part, I went out and rented all of his movies, and then I was terrified.”

Among the many things he learned from working with De Niro, DiCaprio said, the two most important were the older actor’s commitment to character and his commitment to seeking quality roles (“Meet the Fockers,” notwithstanding).

DiCaprio followed “This Boy’s Life” with an Oscar-nominated turn in “What’s Eating Gilbert Grape” (1993) and the well-received “The Basketball Diaries” (1995). His reputation was cemented, but his star power also started to gain wattage with the 1996 release of director Baz Luhrmann’s version of Shakespeare’s “Romeo & Juliet.”

When the “Titanic” role came along in 1997, DiCaprio said, he hesitated because he never sought those kinds of flashy Hollywood roles. But he agreed to do it for no better reason than he hadn’t done something like that before.

Leonardo DiCaprio, the serious young actor, became Leonardo DiCaprio, the superstar tabloid-magnet.

“Nobody could have foreseen the cultural impact of that movie,” he said, shaking his head. “Suddenly, I was on the cover of every teen magazine in the world. I had become the kind of pop symbol that I had tried to avoid my whole career.”

The actor said he did little work for the next two years. “I needed to regroup and to get out of the public eye. I needed to get back to being the type of actor I intended to be when I started out in this business.”

When he emerged from his self-exile, he was no longer the pop-idol actor of “Romeo & Juliet” and “Titanic.” There was a maturity in his acting, and in his choice of roles.

In 2002, he teamed with Steven Spielberg on “Catch Me If You Can” and worked with Scorsese on “The Gangs of New York,” the first of three films with the celebrated director (“The Aviator” and “The Departed” came later).

“It is unbelievable to me that I am working with Martin Scorsese,” he says, unable to hide his giddiness. “He is the great cinematic master of our time, and I am honored and damn lucky to work with him.

“But, at the same time, I feel like I must be doing something right. If Scorsese wants to work with me, I guess I’m becoming the actor I always wanted to be.”