The carcass of the humpback whale spotted Sunday floating in waters off Amagansett — a female, about 3 years old and 29 feet long — showed “evidence of blunt force trauma,” according to preliminary necropsy findings.

The creature’s demise, though, could have resulted from multiple factors, and, as the carcass was significantly decomposed, “it’s difficult to tease out other factors,” said Rob DiGiovanni Jr., senior biologist and executive director with the Riverhead Foundation for Marine Research and Preservation, the procedure Wednesday afternoon.

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Samples were taken and are to be tested for issues related to disease, diet and toxicity, he said. That information will also be shared with the National Oceanic and Atmospheric Administration, which is gathering data on this and two other recently found dead humpbacks in the waters off Rhode Island and Massachusetts.

“It is not clear whether these incidents are at all related,” foundation spokeswoman Rachel Bosworth said Tuesday.

With the three carcasses “in varying levels of decomposition,” the sense is that they died at different times, NOAA spokeswoman Jennifer Goebel said Tuesday.

In such situations, the aim is to test samples for any “harmful algal bloom,” to see if “environmental conditions could have contributed to the mortalities,” she said. When feasible, disease and the possibility of injuries caused by humans are also tracked.

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A team from the foundation Tuesday joined with East Hampton’s marine patrol to photograph and take samples from the whale, which was towed to Little Albert’s Landing in East Hampton, where the necropsy was performed.