A huge sawfish was discovered dead in the Lower Keys, police said.

A large sawfish — a federally protected species — was found dead Tuesday afternoon near a popular boating spot in the Lower Keys, police said.

The 14-foot sawfish, weighing between 400 and 500 pounds, was taken to a Florida Fish and Wildlife Conservation Commission lab in Port Charlotte and a necropsy is pending, said Melody Kilborn, FWC’s southwest region spokeswoman. She said an update will be available Thursday.

The Monroe County Sheriff’s Office said the fish was found dead at about 2 p.m. near Marvin Key.

It was unclear Wednesday what caused the fish’s death, said Office Bobby Dube, a spokesman for the Florida Fish and Wildlife Conservation Commission.

“We do not have that information,” Dube said. “Hopefully, we’ll know a little bit more after the necropsy.”

Lower Keys Marine Deputy Ed Swogger assisted the Florida Fish and Wildlife Conservation Commission in recovering the fish.

The dead sawfish was loaded onto a sheriff’s office patrol boat and was later transported by the lab in Port Charlotte, said sheriff’s office spokesman Adam Linhardt.

The fish has been listed as endangered under the Endangered Species Act since 2003, according to FWC’s website. Under the ESA, it is illegal to catch, harm, harass or kill one.

People may report sawfish sightings at www.myfwc.com or by phone at 844-472-9347.

This is a developing story, which will be updated as more information becomes available.