The beluga whale caught in Norway may not be the only spy of the seas — here are 14 other animals allegedly trained for espionage

• Norwegian researchers believe a beluga whale they captured may be a Russian spy.
• Russia says it uses beluga whale for combat operations, and the US Navy has been open about training animals like dolphins and sea lions.
• Cats have even been trained for spying. Cats!
• Animal spying has also been the subject of conspiracy theories: Numerous countries have accused Israel of avian espionage, though the birds were just tracked for migration patterns.
• Visit INSIDER's homepage for more stories.

Earlier in April, Norwegian marine researchers apprehended a beluga whale. It had been harassing fishers by headbutting their boats and gnawing at their nets, and the scientists were asked to look into it.

What they found was an aggressive whale wearing a harness with the words "Equipment St. Petersburg" stamped onto it. The harness had a spot that could fit a GoPro camera. The researchers believe the dolphin may be a Russian military asset.

"If this whale comes from Russia — and there is great reason to believe it — then it is not Russian scientists but rather the navy that has done this," researcher Martin Biuw told the Norwegian broadcaster NRK.

If the beluga whale is really a Russian spy, it wouldn't be the first time an animal was used for espionage. The United States has a history of training animals to gather intelligence, from cats to dolphins.

"We never found an animal we could not train," Bob Bailey, a former animal trainer and Navy strategist, told Smithsonian magazine in 2013. "Never."

The history of animals being used as spies, however, is also the subject of conspiracy theories. Israel has been baselessly accused of training everything from eagles and chameleons as spies.

Here are 14 animals that have been accused of espionage.

Russia denies that it uses whales as spies. They're just for combat.

The chief reason the scientists at Norway's Institute of Marine Research believe the beluga whale may be a Russian spy is because the harness didn't resemble the kinds use for scientific research.

Marine biologist Audun Rikardsen told the BBC that Russia has a naval base in the region, and that they're known to train domestic whales.

"A Russian colleague said they don't do such experiments, but she knows the navy has caught belugas for some years and trained them — most likely it's related to that," he said.

Viktor Baranets, a Russian military colonel, told a Russian broadcaster that the country doesn't use whales as spies, though he said they're trained for war.

"We have military dolphins for combat roles, we don't cover that up," he said. "In Sevastopol (in Crimea) we have a centre for military dolphins, trained to solve various tasks, from analyzing the seabed to protecting a stretch of water, killing foreign divers, and attaching mines to the hulls of foreign ships."

Militaries of several countries have trained dolphins for reconnaissance.

Since the 1960s, the US Navy has used dolphins to find underwater mines and detect submarines. Russia has also trained dolphins for similar tasks, which has been a subject of recent tension with Ukraine.

In 2015, Hamas accused Israel of using a dolphin to spy on it, but the more likely explanation of that incident is that the animal simply had technology attached to it that tracked migration patterns.

The US Navy trains sea lions in similar ways.

Sea lions have excellent eyesight. And like dolphins, they are good at finding underwater mines and lost objects. The US Navy uses them to retrieve materials like unarmed mines for test reconnaissance missions, according to National Geographic.