A Leonardo DiCaprio film being shot in Africa could hurt livelihoods there by damaging diamond sales, diamond industry leaders have said.
DiCaprio's new film is set during the civil war in Sierra Leone
The Blood Diamond, made by Warner Bros, is expected to show diamond profits being used to fund wars in Africa.
Reduced sales could adversely affect "all of Africa", the World Diamond Council (WDC) told Reuters news agency.
Campaign group Global Witness says the industry has not done enough to tackle trade in "conflict diamonds".
WDC Chairman Eli Izhakoff said: "The people that the movie is trying to help could be hurt the most if it's left without an explanation, since livelihoods in Africa depend on income from diamonds."
At the opening of World Diamond Congress in Tel Aviv, the outgoing president of the World Federation of Diamond Bourses said the problem of conflict diamonds was "practically over".
Shmuel Schnitzer said: "To show a film that will lead the public to think the situation is still the same is an injustice to our industry which has done so much."
The industry says that the introduction in 2000 of a system of certification for rough diamonds - the Kimberley Process - has improved the situation.
Mr Izhakoff said "conflict diamonds" accounted for just 0.2% of the world's rough diamonds.
But Corinna Gilfillan, of Global Witness, said: "Even a small percentage can wreak havoc.
"Wars funded by diamonds have been devastating - they have claimed hundreds of thousands of lives, they have displaced millions of people, atrocities have been committed."
She accused the diamond industry of "paying little more than lip-service" to the system of self-regulation intended to support the Kimberley Process.
The WDC said it was in talks with Warner Bros about the possible inclusion of a scene about the Kimberley Process in the film.
"When all is said and done, they want to be fair," Mr Izhakoff said.
Warner Bros were unavailable for comment.
Directed by The Last Samurai's Edward Zwick, the film follows the battle of wits between a farmer, a smuggler and a group of businessmen for possession of a priceless diamond.
DiCaprio, 31, suffered a minor leg injury during the film shoot in April.