At a now-shuttered adoption agency on the fringes of India's capital, kidnapped toddlers and newborns were being sold for about $8,000 each, no questions asked.

After stumping up cash, prospective parents would inspect the bewildered children at the "Fastrack International" agency and take them home the same day, according to police who raided the premises last month.

"If you wanted a child, one would appear on your lap," joint commissioner of New Delhi police Dependra Pathak told AFP after the successful sting.

A ledger seized during the raid detailed how 23 children had been sold in just a few months and another 76 transactions were being negotiated, some of them involving babies kidnapped from hospitals in other states with the help of doctors and nurses.  

Illegal adoption is a thriving business in India, where more than 100,000 children are reported missing every year, 15 every hour, according to government figures, and activists insist the figures are much higher.

Although many are given up by desperately poor parents in the hope of a better life, others are snatched from hospitals, railway stations and big cities and channelled to couples.

Experts say prospective parents are turning to the black market because of long delays, overcautious officials and complex rules of legally adopting in a country known for its frustrating levels of red tape.

"Why would you wait two years for a baby when you can just pay someone to get you one straight away?" said Lorraine Campos, assistant director of Palna, one of Delhi's oldest adoption agencies and orphanages.  

"Criminals have realised there is money to be made by playing with people's emotions. And there's a nexus involving officials."

Campos has noticed a drop in recent years in the number of abandoned babies being brought to Palna, a non-profit agency caring for some 70 children and registered with the government. She fears some are being handed to criminals instead.

- 'Adopting legally a nuisance' -

Thousands of children are thought orphaned and abandoned in India, although there are no official figures. But only 4,000 were legally adopted in the year to March, according to government data, down from 6,000 in 2012.

Maneka Gandhi, the minister for women and child development, plans to overhaul the "complicated" system to boost those numbers, saying parents waiting years for children is "shameful".

Gandhi is working to simplify the application process, including through a national online tracking system, and a campaign to encourage more parents to use it.

"Adopting them (children) legally is such a nuisance, so if we make it easier then people won't go around pinching babies," she told AFP.

All agencies will be required to register with a central authority and children under their care placed on a national database.

"For every one registered adoption agency, there are 10 which are not (currently) registered. We have no idea what they do," Gandhi said.

Pramod Kumar Soni and his wife Pinki welcome the overhaul. In their two-year wait for a baby, they said they were stonewalled by unresponsive officials.

After 12 years of medical tests and fertility treatment, the couple had turned to an adoption agency near their home before giving up in despair, then finally finding success at Palna.

"They didn't have adequate resources, no documents on the children, no answers about how long the process would take, what the process was or any kind of transparency," Soni told AFP of their experience at the previous agency.

"They only started to show any interest in your case if you had sources (in the department) or influence," the 38-year-old consultant said.

"It was really horrible," Pinki said, staring at their new two-month-old son with his mop of black hair. Left in Palna's "stork basket", the couple can soon take him home after more paperwork is processed.

Children's activist Bhuwan Ribhu also applauds the new legislation, saying there is huge confusion for parents wanting to legally adopt.

And the lack of clear and enforced regulations for agencies means unscrupulous ones are allowed to thrive where already vulnerable children are at risk of being abused and sold for profit.

- 'Tip of the iceberg' -

"People are simply scared of going ahead with the (legal) adoption process. It's also hard to catch and prosecute organised crime syndicates and even harder to convict them," Ribhu, who works with the Bachpan Bachao Andolan (Movement to Save Childhood) organisation, said.

"What happened in Delhi was just the tip of the iceberg."

During the Fastrack International operation, Pathak said officers posed as a couple who were offered a physically healthy but "clearly traumatised" two-year-old boy along with a swaddled newborn.

"The boy has no idea where he comes from or what happened to him," Pathak said.

At the agency's office, now padlocked by police, in a bleak block of flats in the suburb of Dwarka, a neighbour says he saw a stream of people in recent months, some carrying babies and small children.

"There were couples, people of all ages. I asked and they said it was an NGO, a charity," retired air force serviceman George John told AFP.

"There was no reason not to believe them."