Concern over drug-resistant strains of TB is growing, with similar ‘incurable’ TB emerging in Italy and Iran.
Doctors in Mumbai said 12 patients had a “totally drug resistant” form of the infection, and three have died.
The Indian Health Ministry is investigating the cases and has sent a team of doctors to Mumbai.
TB is one of the world’s biggest killers, second only to HIV among infectious diseases.
Normally a patient with TB is given a six to nine month course of antibiotics to eradicate it.
However, new strains of the bacterium have developed which are increasingly resistant to the antibiotics most commonly used to treat it.
Partially drug-resistant TB can now found in countries across the world, and “multi-drug resistant” strains affect countries such as Russia and China
The Indian reports will fuel concerns over the ability of doctors to contain the disease in years to come.
The doctors at the Hinduja National Hospital in Mumbai who discovered it said they had treated patients for up to two years with a battery of drugs, to no avail.
The patients came from slum areas of the city, they said, where close contact between people meant further spread was likely.
The American Centers for Disease Control (CDC) confirmed that the Indian strain did appear to be completely resistant.