The Assam authorities took the engine in their possession on Tuesday.
The locomotive engine of a goods train was "seized" by the Assam Forest Department on Tuesday, weeks after it ran over a 35-year-old female elephant and its calf while passing through the Lumding Reserve Forest. The calf's carcass was found at a distance of one kilometre from its mother, indicating that the train was speeding in the reserve forest, which is against the rules, local authorities said.
The Northeast Frontier Railway said the seizure of the engine was just a "procedural requirement".
"It is not a first of its kind incident and is a procedural requirement for enquiry. There was no operational obstruction and the locomotive is currently in use of Railways," the Northeast Frontier Railway stated.
The incident took place on September 27, and the Assam authorities took the engine in their possession on Tuesday.
"The train was used by the railways for carrying goods to its own project sites. Its speed was so high that it could not stop," Assam Forest Minister Parimal Suklabiadya said.
"When the forest staff of the Lumding range rushed to the spot, they found the carcass of one female elephant, aged about 35 years, and of a male calf, aged about a year. The calf had been dragged nearly a kilometre from the carcass of its mother," he added.
The Assam Forest Department said it pursued the case vigorously under the wildlife protection act and initiated a probe.
A team of forest officials proceeded to the Bamunimaidan Locomotive Shed on Tuesday and seized the engine.
The railways have said a locomotive pilot and his assistant have been suspended over the accident.
"The Assam forest department had informed us. They requested to inspect our engine, wrote to us that it needs to be inspected. We have carried out our own inquiry and it has been found that the train was speeding, which caused the accident," said Subhanan Chanda, spokesperson, Northeast Frontier Railway, said.
"The seized engine was later given back into the custody of railways in view of the continuity of essential services to the public and others. Railways has agreed to pay Rs 12 crore for any loss and damage," the Assam Forest Department said.