Adwaita's shell will be carbon-dated to prove his age

Adwaita, "the only one" in Bengali, was found dead by keepers in Alipore Zoo on Wednesday. His shell cracked some months ago and a wound had developed.

West Bengal officials said records showed Adwaita was at least 150 years old but other evidence pointed to 250.

The shell of Adwaita, an Aldabra tortoise, will now be carbon-dated.

Forestry minister in the West Bengal government, Jogesh Barman said: "Historical records show he was a pet of British general Robert Clive of the East India Company and had spent several years in his sprawling estate before he was brought to the zoo about 130 years ago."

Mr Barman said Adwaita was probably brought from the Seychelles in the Indian Ocean and presented to Clive, an increasing force in the East India Company's military hierarchy.

Shell preserved

Clive was reportedly brought four tortoises but only Adwaita lived

They average about 120kg (265lbs) and are thought the longest-lived of all animals.

The BBC's Amitabha Bhattasali in Calcutta says Adwaita brought in many of the zoo's visitors and when he fell sick for the first time eight years ago with a leg infection a full medical board was instigated to treat him.

The director of the zoo, Subir Chowdhury, said Adwaita's shell would be preserved and kept there.

One zookeeper told the Reuters news agency: "This is a sad day for us. We will miss him very much."

Lord Clive, the son of a Shropshire squire, became a soldier and adventurer who rose through the East India Company.

He won the key Battle of Plassey against the Nawab of Bengal in 1757.

Lord Clive later became an opium addict and committed suicide in 1774 at the age of 49.