The formal trial against the congressional vice president opened Wednesday in a medical sales scandal that has rocked Honduras and led to mass protests against corruption and impunity.

Jorge Rivera, president of the Supreme Court, said he decided to initiate the proceedings against Congresswoman Lena Gutierrez of the ruling National Party, her family members and business associates after reviewing witness testimony and prosecutorial evidence. Rivera was appointed as a special judge because Gutierrez, as an elected official, is immune to regular court proceedings.

Gutierrez and the others face five counts of abuse of public documents and fraudulent drug sales to the Social Security Institute and the Ministry of Health. The prosecution alleges Gutierrez's company, AstroPharma Laboratory, sold the government drugs of dubious quality at inflated prices. The congresswoman, her father Marco Tulio Gutierrez, siblings Ginnette and Julius Caesar, and a dozen partners and employees of the company have denied the charges.

The trial comes at a time when thousands of protesters have held almost daily demonstrations against corruption and demanded President Juan Orlando Hernandez's resignation because of the scandal. Protesters claim several thousand people died consuming adulterated drugs, though no numbers have been confirmed.

Gutierrez spent 18 days under house arrest in July, but paid $907,000 in bail to go free during the proceedings.

Andres Asfura, defense attorney for the Gutierrez family, told The Associated Press he would appeal any decisions against his clients.

Another lawyer for Gutierrez, Eduardo Montes, was stabbed to death two weeks ago in Tegucigalpa by an assailant who said he was defending the people.

Gutierrez has been in congress since 2009 as a member of the ruling National Party. She was vice president of Congress when Hernandez led the legislature.

Irregularities of more than $300 million were discovered in Honduras' public health system by a legislative committee, which issued a report in early June. The report also concluded that a group of businessmen had created shell companies that made contributions to the National Party under the direction of current Vice President Ricardo Alvarez.

A trial against a sitting congress member is unusual in Honduras, an impoverished country of 8.6 million people where government corruption is high.

In neighboring Guatemala, public corruption scandals forced the resignations of President Otto Perez Molina and Vice President Roxana Baldetti, both of whom have been jailed and face graft charges.