A whale stranded for several days in the Seine has died, French authorities said.

It had been removed from the river in preparation for a transfer to a saltwater basin in Normandy in a bid to save its life.

The dangerously thin beluga had no digestive activity for unknown reasons, conservation group Sea Shepherd France had tweeted, saying vet exams were done after it was hauled out of the water following hours of preparation.

But it said in an update on Wednesday morning: “It is with heavy hearts that we announce that the beluga did not survive the translocation which was risky, but essential to give an otherwise doomed animal a chance.

“Following the deterioration of his condition, the veterinarians took the decision to euthanise him.”

The mammal began to have breathing difficulties during the rescue operation, veterinarian Ollivet Courtois said.

Sea Shepherd France earlier said the whale was a male with no infectious diseases and vets would try to re-stimulate its digestion.

Conservationists had tried unsuccessfully since Friday to feed it fish.

Photos showed the white mammal lying on a big net used to get it out of a river lock.

whale
(Sea Shepherd France/PA)

A vet team was planning to transport the 13ft whale to a coastal spot in the north-eastern French port town of Ouistreham for “a period of care”, according to Lamya Essemlali, president of Sea Shepherd France.

The transport was to be made by a refrigerated truck for the 100-mile trip.

Authorities planned to keep the whale in its temporary saltwater home for two to three days of surveillance and treatment before towing it out to sea.

The lost beluga was first seen in the French river, far from its Arctic habitat, last week.

It weighed about 1,700lb.

Authorities said while the move carried its own mortality risk because of the stress on the animal, the whale could not have survived much longer in the Seine’s freshwater habitat.

They were hopeful it would survive after it responded to a cocktail of antibiotics and vitamins administered in the last few days and rubbed itself on the lock’s wall to remove patches that had appeared on its back.