NEW DELHI — Meena discovered she had been sold while riding in an auto-rickshaw headed to New Delhi's red-light district.
The 12-year-old was working as a servant in Calcutta when the homeowner told her of a good-paying job at his sister's house in India's capital. But instead, she was sold to a brothel owner and forced into prostitution for little more than a place to sleep and the occasional meal.
Her ordeal lasted four years and Meena, now 21, says it left her "a very angry person."
"The anger comes suddenly," says Meena, who asked that her full name not be used because of the social stigma.
Beneath the surface of India's rapid economic development lies a problem rooted in the persistent poverty of hundreds of millions of Indians. Rights activists say thousands of poor women and girls are forced into prostitution every year after being lured from villages on false promises.
Much of the attention on human trafficking focuses on the estimated 600,000 to 800,000 people -- about 80% of them women or girls -- who are trafficked across national borders every year, and, in many cases, forced to work as prostitutes or virtual slaves.
But those numbers don't include victims trafficked within countries -- a problem that has long plagued India, a country so large and diverse that victims taken hundreds of miles away where a different language is spoken have little chance of finding their way home.
"This is a challenge to India's contention that it is both democratic and modern," said Ruchira Gupta, founder of the anti-trafficking group Apne Aap Women Worldwide. "In this day and age, when democracy is supposed to exist in India ... we have so many slaves."
It is difficult to track the illicit trade, and the estimates for the number of victims each year vary.
But this much is known: By official estimates, there are 3 million sex workers in India, at least 40% of them children. And thousands are believed to have been unwittingly lured into the work by traffickers, activists say.
Most of the girls come from India's poorer states. A relative or friend approaches the girl's parents about a well-paying job in the city or a chance for marriage requiring little or no dowry.
In some cases, it's the parents who sell the girls. Prices range from several hundred to several thousand dollars.
Traffickers are rarely caught. The U.S. State Department said in an annual report on human trafficking last year that India's response to the problem was weak and prosecutions rare.
In Mumbai, which has the highest concentration of sex workers, only 13 traffickers were arrested in 2005, and none was convicted, according to the State Department. The situation was similar in other cities.
"One of the best ways to prevent trafficking is to increase convictions of trafficking -- and this is not happening," said Gupta. "Women are being rounded up.... but there are very few arrests of men who are running the whole trade."
Deepa Jain Singh, of Ministry of Women and Child Development, said the government was "trying to do more" about the problem of sex trafficking, but she declined to give details.
What becomes of the victims? There are many pitfalls. HIV infections among sex workers are widespread in a country with an estimated 5.7 million people infected with the disease.
Those who escape are often rejected by their families.
Meena was rescued by STOP, an anti-trafficking group, and lives in their New Delhi shelter.
The shelter's goal is to make the girls and women in the house function "like a normal family."
"We want them to go from victim to survivor to activist. It's a long journey," said Roma Debabrata, STOP's founder.