A judge on Wednesday barred the media from a court hearing in a moral damage lawsuit filed against a Mexican filmmaker, whose 2010 documentary shed light on a lack of due process in her homeland.

The ruling by the judge overseeing the case, Maria del Rosario Mancera Perez, affected a hearing in which evidence was presented against lawyer-turned-filmmaker Layda Negrete.

The case concerns the film "Presunto culpable" (Presumed Guilty), made by Negrete and Roberto Hernandez, which tells the dramatic story of Jose Antonio "Toño" Zuñiga, sentenced to 20 years in prison for a murder he did not commit.

Zuñiga was ultimately released after Negrete and Hernandez - also an attorney - took up his case and exposed as false the testimony of key prosecution witness Victor Daniel Reyes, who is now suing the filmmakers for more than 200 million pesos ($15 million).

"Presunto culpable," the highest-grossing documentary in Mexico's history, spurred public indignation at the country's judicial system.

Prior to the start of Wednesday's hearing, Negrete expressed her displeasure at the decision not to allow media access to the courtroom, calling it a violation of the constitutional requirement for public trials.

She said the filmmakers had no intention of sullying the honor of any person in particular, but rather sought to expose "a system that has many deficiencies, particularly in Mexico City."

"Our struggle is to make sure there are cameras placed in the courtrooms, that there are reliable court records, and just as we can see the Congressional, Senate and Supreme Court hearings, we also want to see the criminal and civil trials where such delicate matters affecting citizens are decided day after day," she said.

The attorney said "the right to freedom of expression, to criticize judges, the judiciary" is at stake in her case.

Negrete also said "procedural violations" were occurring in her case that she and her co-defendant have been documenting and seemingly could provide enough material for a "Presumed Guilty 2."