The 31-year-old Florida woman fatally mauled by a massive alligator was kneeling in just three feet of water when the reptile attacked – leaving her boyfriend desperately trying to wrench her from its jaws as it ripped apart her arms, officials said.

Brittany Clark was swimming with her boyfriend and best friend in the Econlockhatchee River at Little Big Econ State Forest – nearly 30 miles inland – Sunday afternoon when the monstrous gator suddenly lunged from the water and locked its toothy maw on her, ripping one arm “completely off.”

“They were hiking and they just stopped to swim,” Florida Fish and Wildlife Conservation Commission spokesperson Chad Weber told reporters at a press conference on Monday.

“She was bitten on both of her arms. The boyfriend was the one that made the phone call. He was trying to get her from the alligator’s mouth, and on the way to the hospital she did pass away from her injuries.”

Weber said the investigation has found no signs that anyone acted maliciously toward the alligator in a way that would have provoked the beast. He said other possible factors may have triggered the attack, including low water levels and territorial behavior.

Shocking audio from the frantic 911 call obtained by The Post revealed details of the horror attack, with a woman describing Clark’s injuries as “horrible,” adding that “one of her arms is completely off and the other one is like attached barely.”

“Bad, real bad please, hurry… she’s losing a lot of blood… we need to stop the blood,” the panicked man could be heard saying in the call.

“Please hurry that’s my best friend,” the woman told operators as she started to wail.

Officials said the victim’s boyfriend managed to hold onto her after the alligator finally released its grip.

Weber said two alligators – one 12-footer near the grisly scene and another 13-foot beast directly at the site of the incident – were captured in the aftermath, with DNA samples sent to a lab to determine if either was responsible for the fatal attack.

Witnesses described the alligator as “very large” – a description consistent with the 13-foot gator.

“We feel like… it’s a good candidate for the gator in question,” FWC Lieutenant Grant Eller told reporters.

“Our lab is going to push it to the front of the line, so we’re hoping to get them back pretty quick.”

The deadly mauling followed a weeklong spate of alligator attacks in Florida – all of them miles from the Sunshine State waterfront – which left a boy and a teenager seriously injured.

Fish and wildlife officials said alligator mating season has been underway since early April, making the animals more aggressive and active.