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We report the discovery of a hydrothermal helium‐3 plume north of the Indian Triple Junction, on the Central Indian Ridge at 19°29′S. Water column δ3He anomalies show a spike of 33.8% at 2460 meter depth, i.e. the highest δ3He anomaly recorded so far in the Indian ocean. The helium‐3 data are correlated with manganese, giving a Mn/3He ratio of 700 mol/cm3 (3.8×104 g/cm3STP). The CH4/3He ratio deduced from available CH4/Mn data in the same area is around 7×106. These values are close to what is observed on water column plumes on the East Pacific Rise. On a regional scale, the 3He distribution over the Indian Triple Junction exhibits a strong δ3He increase at the Ridge crest, which appears to spread eastwards through the deep Indian ocean.