The announcement comes almost two decades after Betancourt was kidnapped by the Revolutionary Armed Forces of Colombia while also campaigning for the country's top office for the Green Oxygen Party, a movement she founded while she was a congresswoman.

"Today I am here to finish off what I started with many of you in 2002," Betancourt said in a conference room where she announced her candidacy.

"I am here to claim the rights of 51 million Colombians who are not finding justice, because we live in a system designed to reward criminals."

Betancourt's run for the presidency starts months after other candidates have already been travelling through the country to campaign for the office, including Gustavo Petro, a former mayor of Bogota who is currently ahead in polls and has tapped into widespread frustration with corruption and economic inequalities that have soared during the pandemic.

Some critics questioned whether Betancourt could make an impact on the presidential elections that will be held in May.

But others said her campaign could also boost interest in the centrist coalition of political parties that will be running a primary in March to select their presidential candidate.

In the primary Betancourt will compete against half a dozen competitors who have been more recently involved in Colombian politics but have struggled in opinion polls.

Betancourt's story is well known in Colombia.

She spent six years in guerrilla camps deep in the Amazon jungle where sometimes rebel fighters would tie her to a tree with metal chains to prevent her from escaping.

Her proof of life videos, in which she asked officials to investigate the circumstances that led to her own kidnapping, and then pleaded with the government to resume peace talks with the FARC rebels were aired widely in Colombia and abroad.

The politician became a symbol of international campaigns seeking peace talks in Colombia and the liberation of FARC hostages.

But her time in captivity ended in 2008 through a military operation, where Colombian soldiers disguised as humanitarian workers snatched Betancourt and several other hostages from the FARC without firing a single bullet.

Betancourt withdrew from public life after being freed, spending much of her time with family in France.

But she returned to Colombia's political scene last year as the country prepared for elections that will be held in May.

While announcing her run for the presidency, Betancourt said she would fight to end impunity for corrupt politicians while addressing economic disparities that have long afflicted Colombia, where protests against inequality shook up local politics last year.

"My story is the story of all Colombians," Betancourt, 60, said.

"While me and my colleagues were chained by the neck, Colombian families were chained by corruption, violence and injustice."

Betancourt said she would fight criminality and prove that Colombia can "change its course".

She added that every week her followers would be invited to "have a beer" with her at her campaign headquarters.

"We will split the cost" she said, after she was asked about who would pick up the tab.

Australian Associated Press