Marine experts criticise €1.5m privately funded operation as humpback’s fate remains unknown after release into Baltic

Marine biologists and whale experts have stepped up their criticism of a privately funded operation to release a humpback whale that was stranded for weeks off Germany’s Baltic coast after it emerged that a tracker fitted to the whale was not working.

The whereabouts and health of the young male whale – nicknamed Timmy after one of the sandbanks it was stranded on – remain unknown three days after it was transported in a water-holding barge pulled by a tugboat to waters off the coast of Denmark.

The rescue initiative, estimated to have cost about €1.5m, was funded in part by Karin Walter-Mommert, the owner of one of the largest racehorse portfolios in Europe.

Walter-Mommert, who confirmed to German media on Tuesday that the tracker was not working, had previously claimed the device was also supposed to transmit information on the animal’s vital signs. This was disputed by some experts and environmental activists, including Greenpeace.