Sailendra Nath Roy, 48, was attempting to cross the river alongside the Coronation Bridge near Siliguri suspended from a 600-foot zip wire Sunday, the BBC reported Monday.
Witnesses said Roy, who was wearing a life jacket, appeared to be stalled after traveling about 300 feet.
"He was desperately trying to move forward. He was trying to scream out some instruction. But no one could follow what he was saying. After struggling for 30 minutes he became still," Balai Sutradhar, a photographer covering the stunt, told the BBC.
Police said he was suspended for nearly 45 minutes before he was brought down. There had been no emergency personnel at the scene.
Doctors at a local hospital said Roy had a "massive heart attack."
Police said he did not have permission to perform the stunt.
In March 2011, Roy was recognized as a Guinness World Record holder for traveling the farthest on a zip line using hair.
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