A Belgian man became the first known fatality of a drug-resistant superbug originating in South Asia, reinforcing fears the germ could spread worldwide after infecting dozens of people in Britain and Australia.

The unnamed patient became infected while hospitalised in Pakistan and died in June, a doctor from the Brussels hospital where he had been treated told Belgian media on Friday (local time).

"He was involved in a car accident during a trip to Pakistan. He was hospitalised with a major leg injury and then repatriated to Belgium, but he was already infected," the doctor said.

Despite being administered colistin, a powerful antibiotic, the patient died, the doctor added.

A second Belgian picked up the bug after being hospitalised following an accident during a trip to his native Montenegro but recovered with treatment back in Belgium in July, another expert said.

"The epicentre of the presence of this bacteria seems to be India and Pakistan, but it appears through contact and travel, its spread is becoming wider," Youri Glupczynski, a bacteriologist from the University of Leuven, said.

The superbug comprises a bacterium containing an enzyme gene called New Delhi metallo-lactamase-1 (NDM-1) that makes it impervious to treatment by almost all antibiotics.

These include drugs known as carbapenems, which are often used as a last resort.

A British journal, The Lancet Infectious Diseases, reported this week that bacteria containing the NDM-1 gene had been found in 37 Britons who had received medical treatment in South Asia.

It said health tourists visiting South Asia risked infection and warned the superbug could spread.

Three cases have been identified in Australia among people who had travelled to India for surgery, said Professor Peter Collignon, Canberra Hospital's head of infectious diseases department.

"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," he said.

"The germ we had was untreatable - there were no drugs we had that could treat it," he added.

'Tip of the iceberg'

Collignon said one of the patients caught the bug in intensive care in an Indian hospital after plastic surgery went wrong. But he said another picked up the bug in the general community, indicating the extent of the problem.

He described the cases as just the "tip of the iceberg".

"It probably is killing lots of people but it happens in the developing world and there's no way of measuring it."

The Lancet study sparked a furious response from India.

"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," the health ministry said in a statement Friday.

But it also emerged that a team of Indian researchers had warned of the superbug in March.

Researchers from the private Hinduja hospital in Mumbai studied 24 infection cases between August and November last year and said they found 22 incidents of NDM-1 bacteria.

- AFP