Brazilian press organizations staged a rally in Rio de Janeiro Friday to highlight concern over a Brazilian journalist, who disappeared while investigating drug trafficking activities.

Speaker after speaker called on the police to do more to solve the case of missing television journalist, Tim Lopes. They spoke at a large demonstration Friday in downtown Rio de Janeiro organized by several press associations to underscore concern over the disappearance. As part of the demonstration, journalists, lawmakers and friends of Mr. Lopes held up a huge white banner with the question: "Where Is Tim Lopes?" written in large black letters.

Mr. Lopes, a reporter with the Globo television network, has been missing since Sunday. He disappeared in a Rio de Janeiro slum while working undercover investigating reports of drug dealing and the sexual exploitation of minors at parties hosted by local drug traffickers. He was carrying a small hidden camera.

TV Globo news director Carlos Schroeder, who participated in Friday's demonstration, says Mr. Lopes may have been recognized by drug dealers. "We don't know what happened but maybe he was recognized because he has done a lot of reports about drug trafficking, and this may have alerted people there and made him a victim of the situation, he said."

There has been an upsurge in drug-related violence in Rio in recent weeks, as rival drug gangs battle over turf. These gangs control Rio's slums and are so powerful that police seldom venture into these areas.

News director Schroeder says the disappearance of Mr. Lopes shows that anyone can become a victim of the drug violence. "Tim is another victim, and I call him a victim even though we don't know his fate, of this unhappy reality which is violence in Rio," he said. "And what this means is that anyone can become a victim, since being a journalist provides no special protection. Instead, unfortunately, journalists now run even greater risks than the ordinary citizen."

Mr. Lopes, an award winning journalist, often went undercover to do his reporting. Last year, he won Brazil's most important journalism award for a report titled "Drug Fair" which was filmed with a hidden camera and showed how traffickers openly sold drugs in a Rio slum.

His disappearance has raised concern internationally. Groups, such as the Committee to Protect Journalists in New York and Reporters Without Borders in Paris, have issued statements expressing concern and calling for a thorough investigation into the case.