A plastic bag was reportedly discovered in the throat of a roughly 17-foot, endangered sei whale that recently washed up on a North Carolina beach.

The whale was found on Sunday on Masonboro Island, WECT-6 reported. Officials with the University of North Carolina Wilmington’s Marine Mammal Stranding Program were subsequently called to the scene.

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Ann Pabst, a member of the Marine Mammal Stranding Program and professor of marine biology at the university, told WECT-6 finding a sei whale stranded in North Carolina is “rare.”

The sea creature appeared to be unhealthy and underweight. Its apparent condition led officials with UNCW and an official with the National Oceanic Atmospheric Association to decide it would be most humane to euthanize the whale.

“This animal was very, very thin. It wasn’t with its mom which it should have been. No food in the stomach, it was clear this animal hadn’t been eating for a while," Pabst told the news station.

A necropsy, an animal autopsy, performed on the whale later revealed a plastic bag was lodged in its throat, WWAY News reported, citing William McLellan, the coordinator of the stranding program.

“It wasn’t able to get food into the mouth so we are not quite sure when that happened,” McLellan said, noting the necropsy revealed the whale also had seagrass in its throat. McLellan added the researchers have "collected a bunch of samples for viral analysis and bacteriology" to study the case further.

While it’s not clear if the plastic was the cause of the sei whale’s death, “it certainly didn’t help the animal in its debilitated state,” Pabst told WECT-6.

Nature photographer Robbie Johnson took to Facebook to share a video of the whale before it was euthanized.

“Urgent. Help needed,” he captioned the video, which had more than 37,000 views as of Thursday afternoon.

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“This is not a sight I wanted to see on Masonboro,” Johnson says in the video.

Sei whales, which are listed as an endangered species, are known for their speed, according to the World Wildlife Fund, which noted they can travel up to 30 miles an hour. They weigh an average of 20 tons and can grow up to 66 feet in length.