A massive whale remains stuck in shallow water just off Germany's Baltic Sea coast, after rescuers failed the latest attempt to save the animal, authorities said on Tuesday.

The roughly 10-meter (32-foot) marine mammal was unable to free itself during the high tide overnight, a police spokesman said.

Rescuers on Tuesday tried to free the whale by sucking up the sand from beneath it.

"Unfortunately, it turned out that the sand was too compact," said Stephanie Gross from the Institute of Terrestrial and Aquatic Wildlife Research (ITAW).

"We will try everything to save the animal," local mayor Sven Partheil-Böhnke vowed.

A fresh attempt is to be made on Thursday, as different equipment is en route to the scene, but it will not arrive until Wednesday afternoon, she added. 

One of the largest animals in the world

The whale was first spotted early on Monday near Niendorf in the northern state of Schleswig-Holstein.

Early signs indicate that it may be a humpback whale — one of the largest animals on earth with distinct pectoral fins, or flippers.

Rescue workers have been trying to free it from a sandbank since midday on Monday, with the help of boats to generate waves, drone technology, as well as support from volunteers and experts.

Although their mission has not been successful yet, they managed to partially free it from netting that had become wrapped around its body.

Unclear how whale got stuck

Public broadcaster NDR reported earlier that the whale could be heard periodically making "deep, muffled" noises and that it appeared weak.

Police used barriers on land to ensure it is not disturbed by onlookers.

It is still unclear why the whale ended up in the Baltic bay's shallow water. Stephanie Gross from the Hanover-based Institute for Terrestrial and Aquatic Wildlife Research, said it may have been sick, injured, exhausted, or simply unlucky.

Marine conservation group Sea Shepherd says the mammal is likely a young male on migration and believes it could be the same whale repeatedly sighted in the area earlier this month.

Edited by: Wesley Dockery