A controversial research project in Norway on whales' hearing was suspended after a whale drowned.

A controversial research project in Norway on whales' hearing was suspended after a whale drowned, researchers said on Wednesday, as activists slammed the "cruel and pointless" experiments.

Under the project, run by the Norwegian Defence Research Establishment (FFI) each summer since 2021 minke whales are captured in the Lofoten archipelago and submitted to hearing tests before they are released into the wild again.

The experiments, which are run in cooperation with the US National Marine Mammal Foundation, are officially aimed at gathering knowledge in order to set limits on how much noise humans should be allowed to make in the ocean.

They have been criticized by animal rights defenders and scientists who consider the project dangerous.

In the night between June 2 and 3, bad weather damaged the project testing site, causing a barrier line to break free. A whale became entangled in it and died, the FFI said.

The incident occurred before the official start of this year's experiments.

The project has been put on hold indefinitely while the incident is reviewed and the site repaired.

"Our aim is to protect Minke whales and other baleens, and to protect them from harmful human-made noise," Petter Kvadsheim, chief researcher at FFI, said.

"We will continue our work on this. The health of the animals is our main priority in this experiment."

The project had been due to continue until the summer of 2024.

'Failed for three years'

In an interview with AFP, Kvadsheim blamed the incident on bad weather rather than the experiment, and said he hoped the project could resume "in the next few days".

"It's never been done before and unexpected things can happen," he said, adding that it was unfolding "step by step" and "on schedule".

He said only "a handful" of whales were needed to complete the project.

One whale entered the testing site the first year, in 2021, but it quickly escaped.

In 2022, another minke was captured but it was released immediately because it showed signs of stress.

The US Animal Welfare Institute (AWI) called on the Norwegian and American authorities to "immediately and permanently shut down this project."

"Researchers have now failed for three years to get any data, subjected several whales to the stress of being herded into a large net enclosure, and now caused the death of a whale," AWI noted.

In 2021, 50 international scientists had written to the Norwegian government to protest against the experiments.

"We have warned that these cruel and pointless experiments would lead to whales being killed and it is sadly ironic that this poor minke has died even before the experiments have got underway," said Danny Groves, a spokesman for the Whale and Dolphin Conservation.

"No whales should have to face being bundled into a cage and have electrodes implanted under his or her skin. These experiments should be halted permanently," he added.