India's government said Wednesday it would ban foreigners from using surrogate mothers in the country, a move likely to hit the booming commercial surrogacy industry.
Ranks of childless foreign couples have flocked to the country in recent years looking for a cheap, legal and simple route to parenthood.
Health industry estimates put the size of India's surrogacy business at nine billion rupees ($138 million) and growing at 20 percent a year.
But critics have said a lack of legislation encourages "rent-a-womb" exploitation of young, poor Indian women.
In an affidavit to the Supreme Court on Wednesday the government said it "does not support commercial surrogacy".
"No foreigners can avail surrogacy services in India," it told the court, which is hearing a petition regarding the industry, adding that surrogacy would be available "only for Indian couples".
Thousands of infertile couples, many from overseas, hire the wombs of Indian women to carry their embryos through to birth.
India, with cheap technology, skilled doctors and a steady supply of local surrogates, is one of relatively few countries where women can be paid to carry another's child.
Surrogacy for profit is illegal in many other countries.
The process usually involves in-vitro fertilization and embryo transfer, leading to a rise in fertility centers offering such services.
A top fertility expert branded the government's move discriminatory, while a leading women's activist warned it could push the industry underground and out of reach of regulators.
"Banning commercial surrogacy will send some couples onto the black market and deprive other couples of the chance of children," Ranjana Kumari, director of the Center for Social Research, told AFP.
"Our research shows many surrogates do not have health insurance and are paid poorly, among other issues," she said, adding that stronger regulation rather than an outright ban was needed.
The private petition to the top court seeks a halt to the importation of human embryos for commercial purposes.
Earlier this month the court in Delhi expressed its concern and ordered the government to spell out measures for regulating the industry.
The government's affidavit, presented to the court by Solicitor General Ranjit Kumar, said it would "require some time to bring the law in place".
"The government will prohibit and penalize commercial surrogacy services," it said.
The government has been consulting women's groups and the health industry on a draft bill, the Assisted Reproductive Technology, that seeks to regulate the industry.
Clinic owners denied ill-treatment of surrogate mothers, saying it is in their interests to treat the women well so they produce healthy babies.
Dr Nayana Patel, one of India's leading fertility specialists, said the move discriminated against foreigners who were also desperate to have children.
"Yes, there need to be strict checks and counter checks but banning foreigners is not the answer. It's inhuman," Patel told AFP.
"There is no exploitation, it's a voluntary contract between human beings involving an exchange of money. What's wrong with that?"
"It's a dignified earning. Instead of women working as maids, they can be surrogates," said Patel, who runs the Akanksha fertility clinic in the western state of Gujarat.
The latest move comes after India issued new rules in 2012 barring foreign gay couples and single people from using surrogate mothers to become parents, drawing sharp criticism from gay rights advocates and fertility clinics.
The existing rules say foreign couples seeking to enter into a surrogacy arrangement in India must be a "man and woman (who) are duly married and the marriage should be sustained at least two years".
The cost of surrogacy in India generally ranges from about $18,000 to $30,000, of which around $8,000 goes to the surrogate mother. The figure is roughly a third of the US price.