Jacinta Francisco Marcial was released last week after prosecutors decided not to contest an appeal of her 21-year sentence. London-based rights group Amnesty International demanded that she be compensated for the time spent locked up.

The Attorney General's Office said in a statement that she would not be compensated because prosecutors never proclaimed her innocence, deciding only that there was "reasonable doubt" in her conviction.

Marcial and others were convicted of holding federal agents hostage during a market raid to confiscate pirated goods. Marcial denied involvement in detaining the agents.

Mexico's Indians, many of whom don't speak Spanish, have a right to an interpreter in legal proceedings under current law, but none was apparently provided to Marcial, an Otomi Indian, during the initial stages of her trial.

Prosecutors said a review of her case turned up "contradictions in the statements of federal agents," with some witnesses saying they saw Marcial at the scene and others saying they didn't.