Former Argentine President Cristina Fernandez de Kirchner waves to supporters as she leaves her home on her way to a court to answer questions over a probe into the sale of US dollar futures contracts at below-market rates by the central bank during her administration, in Buenos Aires, Argentina, April 13, 2016. [Photo/Agencies]

BUENOS AIRES - Former Argentine President Cristina Fernandez on Wednesday refuted allegations of corruption, saying the government is trying to silence her by putting her behind bars.

After being summoned by a federal judge to testify about suspicious operations made by the country's central bank in the final days of her presidency, Fernandez addressed a massive rally of supporters gathering outside the courthouse, state news agency Telam reported.

"Thousands of demonstrators" cheered Fernandez as she delivered an impassioned speech, telling the crowd: "They can summon me 20 more times, they can imprison me, but what they cannot do is to shut me up."

Fernandez was accused of playing a role in the central bank's decision to sell dollars on the futures market at an artificially low price in the months before leaving office in December.

At the time, there was a large gap between the official rate of the Argentine peso against the U.S. dollar and the rate on the black market. Judge Claudio Bonadio said selling dollars below market rate cost the state about 5.2 billion dollars, and allowed buyers to make a lot of money on the transaction.

In a written statement she presented to Bonadio, Fernandez denied any wrongdoing and accused the government of bringing "trumped-up" criminal charges against her to try to put her away.

Her lawyer, Carlos Beraldi, also submitted a petition to have Bonadio "recused," or disqualified.

Fernandez, who served as Argentine president from 2007 to 2015, instead criticized Mauricio Macri, her pro-business and pro-U.S. successor, whose austerity measures have sparked nationwide protests shortly after he took office.

"I have never seen so many calamities produced in the past 120 days," Fernandez said.

Addressing her supporters, Fernandez said she had nothing to hide and warned that the Argentine government was undergoing a political shift to the right, as was Latin America in general.

"I am not afraid. I voluntarily renounced having immunity. I don't need it," Fernandez said, adding that "the (political) regression taking place" in Argentina "is being replicated regionwide."

"This is a political, judicial and media pattern that has spread throughout the region to link national and people-based projects with corruption, so that ... by the time it has blown over, you won't even remember your own name," she said.

In a separate case, Fernandez has also been accused of money laundering.