Officials in Europe are investigating a strange case of mutilated Holstein cows washing up dead on beaches along the Baltic Sea in Denmark and Sweden.

Some of the cows were found with bullet wounds, and others had their legs banded together, but all of them had parts of their ears clipped off, which investigators suspect was done to removed the identification tags used to track the cows, according to various media reports.

Since Dec. 29, eight dead cows have been found on beaches in Sweden and three have been found in Denmark, according to The Associated Press.

The incidents appear to be connected, as all of the cows were the same breed and each of the beached cows was missing its identification tag on its ear.

"We are investigating the whole thing as an environmental violation. I would guess that the cows have been on board a vessel and have been thrown overboard," one investigator said, according to a report on Live Leak.

Dumping livestock into the sea in such a manner is illegal, but it cannot be determined whether the cows were dumped in Danish, Swedish or international waters.

In an attempt to trace possible origins of the deceased cows, investigators are collecting data on ships carrying livestock that passed though the region in recent weeks.

Ingvar Wennersten, deputy chief prosecutor in the municipality of Malmoe, Sweden, said at least two of the cows washed up in Sweden had been shot, according to the Daily Mail.

Danish police officer Boje Joergensen told the AP that some of the cows had their hind legs tied together with blue rope, which was probably done so that the animals could be lifted with a crane.

Swedish police said that a veterinary examination of the cows found there revealed no traces of disease.

Holstein Friesian cattle, typically refered to as Holsteins, are black and white dairy cows.

Click here to see photos of the beached cows.