Venezuela's attorney general has indicted the opposition leader Maria Corina Machado on charges of being involved in an alleged plot to kill President Nicolas Maduro.

The attorney general's office announced Wednesday that "whoever, from inside or outside the national territory, conspires to destroy the nation's republican political style will be punished by eight to 16 years in prison."

Machado had agreed to give testimony at a closed hearing in the nation's capital, Caracas, on Wednesday, relating to her participation in the alleged plan.

She has consistently maintained that she is innocent and unaware of the supposed plot to assassinate Maduro.

"This is the price I have to pay for speaking the truth in Venezuela," she said prior to the hearing.

The opposition leader had described the allegations as "political persecution" and an attempt to silence her.

Following her indictment, Machado addressed her supporters on the steps of the attorney general's office.

"Our only option is to fight for democracy and freedom," she said.

Machado is seen as a poster girl for the opposition. However, many Maduro backers believe she is out of touch and aims to overthrow the government.

Earlier in the year, the hard-line politician had coordinated public protests against the ruling Socialist government, along with fellow opposition leader Leopoldo Lopez. Lopez was arrested in February in what some have called a move to silence Maduro's political enemies and is currently behind bars.

Maduro dismissed the protests as an attempt to destabilize the nation's government.

The investigation began in March, after officials alleged that they had information about a plan to murder the president involving Machado and several other politicians. In May emails were made public purporting to show Machado conspiring with others, including the US ambassador to Colombia, to assassinate Maduro.

The president came to power after narrowly winning last year's elections, succeeding the late Hugo Chavez.

Critics say since then he has increased the state's influence over the judiciary and electoral systems, and is trying to silence potential political opponents before next year's legislative elections.

He claims there have already been at least five attempts on his life - and many more acts of sabotage and conspiracy against him since taking over the top job.

Machado, who was a member of Venezuela's National Assembly before being forced out in March, also accused the government's legal team of using the charges as a tactic to deflect attention away from the nation's unstable economic situation. Almost all of Venezuela's export earnings come from crude oil, but, with global petrol prices continuing to fall, the government is being forced to cut spending. The nation already has the highest rate of inflation in the world.

an/mkg (Reuters/AFP)