An American journalist, arrested earlier this month in the Darfur region of Sudan, has been charged with spying by the Sudanese authorities.
Salopek is a two-time Pulitzer Prize winner
Paul Salopek, a Pulitzer Prize winner from the Chicago Tribune, was detained along with his driver and interpreter.
At the time he was on an assignment for the National Geographic Magazine on the Sahel region of sub-Saharan Africa.
The magazine's editor, Chris Johns, has appealed for his release, saying Mr Salopek was simply there to report.
A court in the town of El Fasher in Darfur charged Mr Salopek with criminal espionage, reporting false information and entering Sudan without a visa.
But Mr Johns insisted that Mr Salopek "had no agenda other than to fairly and accurately report on the region".
"He is a world-recognised journalist of the highest standing, with a deep knowledge and respect for the continent of Africa and its people."
An earlier statement from the magazine, for whom Mr Salopek is working during a leave of absence from the Chicago Tribune, said:
"National Geographic magazine vigorously protests this accusation and appeals to Sudan for his immediate release and the release of two Chadians assisting him."
Ann Marie Lipinski, the editor of the Chicago Tribune, described Mr Salopek as "one of the most accomplished and admired journalists of our time," adding that "he is not a spy".
"We are deeply worried about Paul and his well-being, and appeal to the government of Sudan to return him safely home," Me Lipinski added.
A judge in El Fasher said Mr Salopek would face another hearing in September on the charges of entering Sudan without a visa.
Earlier in August, a Sudanese court sentenced the Slovenian president's envoy to two years in jail for spying and entering the country illegally.
Tomo Kriznar was involved in the peace process between Sudan's government and rebels in the troubled Darfur region.
The envoy, a well known human rights activist in Slovenia, was also jailed for publishing false information.