The mysterious sighting of dogs with bright blue fur in the Chernobyl Exclusion Zone has stirred curiosity and speculation among onlookers. Captured in photos earlier this year, these vibrant canines were spotted wandering the grounds of the infamous 1986 nuclear disaster site in Ukraine, leading to a flurry of online theories ranging from radiation-induced mutations to otherworldly phenomena.

Contrary to these imaginative explanations, a scientific advisor associated with the organization responsible for the care of these stray animals has clarified the true source of their unusual coloration. Timothy Mousseau, from the University of South Carolina, addressed the speculation via the Dogs of Chernobyl Facebook page, dismissing the radiation theories as far-fetched.

“The blue hue likely resulted from the dogs rolling around in a spilled port-a-potty, which contained blue dye, as dogs often engage in such behavior,” Mousseau explained.

Despite the initial intrigue, the explanation behind the blue dogs of Chernobyl is far more mundane than many had imagined. This peculiar phenomenon, vividly captured in images shared by the Clean Futures Fund, serves as a reminder of the unpredictable and sometimes comical antics of our four-legged companions.

Photos taken earlier this year showed several dogs with bright blue fur wandering the site of the 1986 nuclear disaster in Ukraine. (Clean Futures Fund via Storyful )

Mousseau noted this behavior is similar to how some dogs are drawn to cat litter boxes.

“The blue coloration was simply a sign of the dog’s unsanitary behavior!” Mousseau said. “As any dog owner knows, most dogs will eat just about anything, including feces!”

Despite the social media speculation, the dogs’ blue fur does “not reflect any kind of mutation or evolutionary adaptation to radiation,” he added.

Dogs of Chernobyl, the program that cares for the roughly 700 dogs in the Chernobyl Exclusion Zone, first shared images of the blue-tinted dogs in October.   (Clean Futures Fund via Storyful )

Dogs of Chernobyl, the program that cares for the roughly 700 dogs in the Chernobyl Exclusion Zone and is affiliated with the nonprofit Clean Futures Fund (CFF), first shared images of the blue-tinted dogs in October.  

At the time, the group had been unable to capture the animals to determine the source of their unusual coloring.

“We are on the ground catching dogs for sterilization, and we came across three dogs that were completely blue,” Dogs of Chernobyl posted to Instagram. “We are not sure exactly what is going [on]. … We do not know the reason, and we are attempting to catch them so we can find out what is happening.”

FILE PHOTO: Two stray dogs with bright blue fur walk along the street. (Mikhail Svetlov/Getty Images)

Many dogs were left behind following the Chernobyl nuclear plant explosion, when more than 120,000 evacuees were told to leave immediately, according to CFF.

“The evacuees were not allowed to bring anything that they could not carry, and their pets had to be left behind,” the CFF website notes. “They were told they would return in 3 days, but they were never allowed to return. Their pets became abandoned.”

Timothy Mousseau did not immediately respond to Fox News Digital’s request for comment.