An adult Indian elephant that became trapped in a swamp in Bangladesh after being caught up in raging floodwaters has died after weeks of struggling for survival.

Tapan Kumar Dey, a former forest conservator who was overseeing the rescue operation said the elephant died early Tuesday.

The reasons for the death of the elephant named "Bangabahadur," or Hero of Bengal, were not immediately clear.

Monsoon-triggered flooding had carried the male elephant from upstream India before he became trapped in a swamp in Bangladesh's Jamalpur district three weeks ago.

Authorities had planned to rescue it and move it to a safari park near the capital Dhaka.

Heavy downpours have flooded vast area of eastern India since monsoon rains began in June.