Six respected Indian institutes, including the University of Madras in Chennai, took part in the study, and eight of the 31 researchers involved work in Indian institutions, according to the Indian Express newspaper.
Still, the Indian health ministry reacted angrily to the findings, calling them "unscientific". The Indian health secretary told the Indian Express she was "shocked" that The Lancet published the study.
"We strongly refute the naming of the enzyme ... and also refute that hospitals in India are not safe for treatment including medical tourism," the ministry said in a statement.
"To link this with the safety of surgery in hospitals in India and citing isolated examples to show that ... India is not a safe place to visit, is wrong."
"It probably is killing lots of people but it happens in the developing world and there's no way of measuring it"
Peter Collignon, head of the infectious diseases department at Canberra Hospital
The ministry said that the report was scaremongering, but did admit that the bacteria could circulate widely with international travel.
The NDM-1 gene was discovered last year by Timothy Walsh of Cardiff University in two types of bacteria carried by a Swedish patient who had been admitted to a hospital in India.
Concern has been heightened because the germ produces an enzyme that is resistant to very strong, last resort antibiotics.
The researchers said that 37 people had been found to be carrying the bug.
Peter Collignon, the head of the infectious diseases department at Canberra Hospital in Australia's capital, also said that three Australians had brought the bug to the country from India.
He said that the cases, including one person who travelled to India for plastic surgery, were the "tip of the iceberg".
"There may well be more because it's difficult to pick up this particular gene unless you've got sophisticated testing," Collignon said.
"We found this multi-resistant, untreatable bug in their urine, luckily not causing too many problems to that person. But it's a real problem if it spreads to others.
"The germ we had was untreatable - there were no drugs we had that could treat it."
Collignon said while one person had contracted the gene during botched plastic surgery, another had worringly picked up the bug in the general community.
"It probably is killing lots of people but it happens in the developing world and there's no way of measuring it."
Collignon, who sits on the World Health Organisation board on antibiotics, said that "abuse" of antibiotics in medicine and agriculture has led to the superbug.
"When you link it to our antibiotics policy ... say it is dangerous to get operated on in India and that you will get more infections, that is totally irrational"
V M Katoch, director general of the Indian Council of Medical Research
He called for a international crackdown on such widespread use and a hygiene campaign to stop the spread of bacteria.
"All of these systems are interlinked through our food. Wherever we use antibiotics and wherever we over-use them we will get superbugs develop and we will get problems," Collignon said.
Medical tourists are flocking to South Asia, with new hospitals offering a range of services with well-trained staff, at about half of the price of western Europe.
V M Katoch, director general of the Indian Council of Medical Research, said that multiple drug resistance was "always a concern".
"But when you draw conclusions that link it to a specific country, then you are going too far," Katoch said.
"When you link it to our antibiotics policy ... say it is dangerous to get operated on in India and that you will get more infections, that is totally irrational."
Professor Hugh Pennington, an expert in bacteria, told Al Jazeera: "The numbers are still very small of patients who carry the bacteria. But it is spreading quite quickly."
Pennington said that of the 37 cases found in the UK, 17 of the patients had been to India or Pakistan, suggesting that they picked up the bug in one of those nations.
While Pennington said that the research would have been of the highest quality, "one might be able to doubt where the enzyme came from".
"We have one or two antibiotics left ... but if this got widespread we would be in difficulty. Not at the end of the road but getting close."