The St Tammany Parish Sheriff’s Office said the parish coroner’s office was working with investigators to determine whether the remains were those of Timothy Satterlee, 71, who has been missing since the August 30 attack.
Ida caused widespread flooding and cut off electricity and telephone services in parts of southern Louisiana when it made landfall on August 29.
Mr Satterlee was attacked outside his home, surrounded by flood water, in the New Orleans suburb of Slidell, on the north shore of Lake Pontchartrain.
Authorities said Mr Satterlee’s wife heard splashing and left their home to see the alligator attacking her husband. She managed to drag her seriously injured husband to the steps of their property.
She used a small boat to reach higher ground for help. But, when she and her deputies returned home, Mr. Satterlee was gone.
Sheriff’s deputies were joined by federal and state wildlife officers in the search for the reptile.
A trap set by alligator hunters captured the 500-pound animal on Monday morning.
St Tammany Parish Sheriff Randy Smith said on Facebook: “This is a horrible tragedy and my sincere condolences and sympathy go out to the Satterlee family.
“I know today’s findings don’t bring their loved one back, but I hope it can give them some sort of closure.
“I am very proud of the hard and continuous work of my assistants and other agencies who have helped me, and I hope their persistence in finding this alligator will help the family cope with their loss. We will continue to keep them in our prayers. ”