BANGKOK — An American journalist whose work for a conservation website exposed environmental degradation and corporate malfeasance in Indonesia has been jailed by the country’s immigration authorities on suspicion that he violated the conditions of his visa, his attorney said on Wednesday.

Philip Jacobson, an editor for the environmental science website Mongabay, was traveling on a business visa in the city of Palangkaraya on Borneo when he was detained on Dec. 17 and ordered to remain in the city while the authorities investigated his case, according to an article on Mongabay’s website.

On Tuesday, the immigration authorities took him into custody and put him in the main jail in Palangkaraya, said his lawyer, Aryo Nugroho, the head of Indonesian Legal Aid in the city.

Mr. Aryo said the case appeared to focus on Mr. Jacobson’s use of a business visa instead of a journalism visa during his travels in the country and did not appear to be motivated by concern over a particular article produced by Mongabay.