A lone dolphin has followed a sailing boat carrying a cargo of fair trade coffee and rum from the French coast to Amsterdam’s port and seems reluctant to leave the ship, experts said on Sunday.

The animal is fit and healthy but rescue organisation SOS Dolfijn said the brackish water is not good for the animal and it may not be able to find enough food.

‘The animal seems to have developed a close connection with the ship and stayed swimming with it through the sluice gates and now it is in the port,’ said spokesman Eligius Everaarts.

Attempts to lure the animal back to the open sea are being hindered by the fact that it will have to swim though the sluices at IJmuiden, which means the rescue operation can only happen when the gates are open.

SOS Dolfijn tried to make the animal follow their boat but after a while it turned and went back to the ship. The schooner which it followed cannot be used to guide the animal back because it must be unloaded first.

Catching the animal is not option either, the organisation said, because the port is a large area and the manoeuvre could put the animal’s life in danger.

‘It may make it out on its own bit that will depend on the sluices,’ a spokesperson for the organisation said.

The adult bottle nose dolphin has been identified as Zafar, a dolphin which has been spotted on the coast of France in 2018 where it was observed to interact with divers.

The organisation said it will continue to monitor the situation.

Update Sunday evening: According to broadcaster NOS, the dolphin was successfully encouraged to return to the sea on Sunday afternoon.