One of Latin America’s most celebrated journalists, whose work has toppled presidents and set off criminal investigations into government wrongdoing, was recovering from an aggressive bout of chemotherapy when he got more bad news: A Peruvian prosecutor was investigating him for bribery.

The journalist, Gustavo Gorriti, 76, the top editor at an investigative news media organization in Peru, is no stranger to trouble.

In the 1990s, he was kidnapped by members of a secret death squad that Peruvian investigators later determined was headed by former President Alberto Fujimori. Mr. Gorriti had spent years reporting on corruption and human rights violations by the Fujimori’s government.

More recently, he helped expose an enormous bribery scandal known as Operation Carwash that has led to the arrest and resignation of government officials across Latin America.

Now, Mr. Gorriti himself is facing imprisonment.

Peru’s attorney general has accused him of bribery, claiming that he provided positive coverage in exchange for government leaks. Mr. Gorriti denies the charges.

Journalists and free speech supporters say the accusation is politically motivated, meant to punish Mr. Gorriti for his past investigations.