QUITO, Pichincha (AFP) - Sent to a centre offering to "cure" her attraction to women, Denisse Freire was raped and tortured - in a practice Ecuadoran authorities admit has been tolerated for too long.

The country of 15.8 million people has at least 80 unlicensed drug and alcohol rehab clinics, many that are also used for anti-gay conversion therapy, Health Minister Carina Vance, who is openly gay, said.

Two people, admitted for addiction issues, died last year at the clandestine centres, she told foreign reporters at a press conference, adding that authorities have begun to crack down.

At these centres, "we have reports of physical attacks, the use of ice water on inmates," Ms Vance said. "We have lesbians who have reported what the clinics called 'sex therapy,' but which consists of being raped by men," the minister said.

Ms Freire, now 25, was just 15 when her mother discovered her in her room with a female schoolmate.

Outraged, she sent her daughter to a "Christian camp" in a remote area in south-eastern Ecuador.

There, Freire said, "they tortured me with electric shocks, didn't let me bathe for three days, gave me almost nothing to eat, hit me a lot, hung me by my feet.

"They told me it was for my own good." There were also sexual punishments, all aimed at ridding the young girl of her homosexuality.

The centre was nominally a evangelical Christian rehabilitation clinic for drug and alcohol addiction. But Ms Freire said she was there with four other young people - all because they were gay. After two months, Freire escaped.

Her case was not an isolated one. Authorities say the inhumane practice is a wide-ranging problem that has ensnared even government officials - such as the health ministry official who was recently subject of a criminal complaint after it emerged she owned a clandestine clinic offering therapy against homosexuality.

"We are talking here about a mafia, a network that operates nationally in each of the provinces, which are violating human rights," Health Minister Vance said.

Since March 2012, authorities have closed 18 rehab clinics: 15 for human rights violations and three for violations of health standards, the ministry said.

Still, more clinics remain.

In June, Zulema Constante, a 22-year-old psychology student, escaped a clinic in the eastern city of Tena, where she said her family had forcibly admitted her to cure her of homosexuality.

She was handcuffed and locked in a straightjacket. "I had to pray, they gave me food poisoning, forced me to clean toilets with my hands, and told me I was wrong to be a lesbian," she told reporters.

The clinic is owned by a health official in the region.

Constante's girlfriend, Cynthia Rodriguez, launched a social media campaign to report the case, building public pressure that allowed her to be set free after three weeks.

But activists say too many complaints are unsuccessful.

"Why?" asks Leah Burbano of the Lesbian Women and Woman Movement. Because the people forcing the victims into the clinics "are family and that creates an emotional weight."

"But this is not a struggle between parents and children. It's a struggle against these clinics." Ecuadoran law authorises forced treatment for addicts with approval from a judge.

But health minister Ms Vance emphasised in no case is the forced treatment allowed to seek to "cure" homosexuality.