Prosecutors in Honduras have charged the vice president of the nation's congress with fraud, falsification of documents and crimes against public health in a widening corruption investigation.

The investigation into the fraudulent sales of medicines to the government has brought thousands of Hondurans into the streets in protest the past two weeks.

Congress vice president Lena Gutierrez has been a federal legislator since 2009. From 2010 to 2014, she was No. 2 under congress chief and now Honduran President Juan Orlando Hernandez.

Gutierrez is co-owner of the company Astropharma, together with her father and two siblings. She told local television she was surprised by the charges and will prove her innocence.

The charges came one day after the army took over Honduras' public hospitals and medicine stockpiles.