They were working for a Catholic bishop and had clear-cut orders from Pope Francis himself -- probe reports of pedophile priests in a city in Colombia.

What these two investigators -- two Catholic women with experience conducting criminal probes -- found was an utter bombshell: a network of predatory clergymen that sexually abused at least 20 people, reportedly taking turns with one of them.

The abuse was committed in Villavicencio, a central Colombian city of half a million people with a cathedral in the town square, and parts of the surrounding area that fall under one archdiocese.

The pope says fighting clergy sex abuse is one of his priorities, and in 2019, he told the bishop of Villavicencio, Oscar Urbina, to investigate alleged abuses by priests.

A boy play in the town square of Villavicencio, Colombia, where a clergy sex abuse scandal was uncovered A boy play in the town square of Villavicencio, Colombia, where a clergy sex abuse scandal was uncovered Photo: AFP / Juan BARRETO

The bishop turned to Olga Cristancho, 68, a seasoned former prosecutor, and Socorro Martinez, 59, who used to work in the attorney general's office and has experience probing massacres in Colombia, a country that endured decades of conflict involving government forces, leftist rebels, right-wing paramilitaries and drug traffickers.

But shortly after the church probe began, these two women distanced themselves from Urbina, suspecting a cover-up and launching an investigation of their own.

Cristancho said she was shocked by what she learned.

"I never dreamed of such a thing," she told AFP. The women sleuths gathered evidence despite what they called interference from the bishop.

Among their finds: one man told them priests started abusing him at age 15 and took turns doing so.

Socorro Martinez, the other investigator in the scandal, says the church considers her an enemy Socorro Martinez, the other investigator in the scandal, says the church considers her an enemy Photo: AFP / Juan BARRETO

Priests also used code words to communicate with each other, Cristancho said.

"One would say to the other, 'I am sending you a CD,' but that meant, 'I am sending you that boy'," Cristancho said.

The two investigators sent the conclusions of their effort to the Vatican in 2019 -- and are still awaiting a response.

A book published last year by journalist Juan Pablo Barrientos is based on their work and goes further, with testimony implicating 38 priests in sexual abuse. The church tried in vain to censor it.

Olga Cristancho, an attorney and one of two women who uncovered the abuse, is seen at her home Olga Cristancho, an attorney and one of two women who uncovered the abuse, is seen at her home Photo: AFP / Juan BARRETO

The church has quietly sent away 20 of the priests accused of abuse. So far, two others are in prison after being convicted of abusing a 13-year-old choir boy.

"It will be up to the courts, both judicial and canon, to render a verdict," said William Prieto, a priest and spokesman for the archdiocese, in the church's only public comment on this scandal.

Colombian prosecutors opened their own investigation, and in late January, Cristancho and Martinez gave testimony. The attorney general's office declined an AFP request for comment.

Urbina's office also declined AFP requests for comment.

One of the victims is a man who for this story is being identified as Miguel.

As a child, his family used to vacation in Villavicencio, and his parents would send him to a rectory to see an uncle who was a priest.

There, a seminarian abused Miguel, forcing him into oral sex.

"He knew how to manipulate my uncle's trust, my family's trust, so that I would go to bed with him," Miguel said in an interview during which he hid his face.

As an adult, he said he suffered from suicidal thoughts and depression.

"I wanted to end my life," he said. "I felt dirty."

He filed a complaint with church authorities but has not received an answer.

Martinez says she hardly goes out anymore, and her son received a call in which she was described as a "sapa," or snitch.

The church hierarchy considers her an enemy, she said.

"We were the pebble in their shoe," Martinez said.