A Mexican federal judge has ruled that charges filed against a leader of the Zapatista rebel uprising of 1994 are no longer valid.

The rebel known as "Subcomandante Marcos" was charged 21 years ago with rebellion, terrorism and other crimes.

Mexican law says charges expire when half of the potential prison term for the most serious crime has passed. According to the court, in Marcos' case that would have been a 40 year-sentence for terrorism.

Mexico's government has identified Marcos as Rafael Sebastian Guillen Vicente, but he has never confirmed it. In 2014, Marcos announced he was retiring that nom de guerre and would instead be called "Galeano" in honor of a killed rebel.