Authorities in south Louisiana recovered the body of a 29-year-old pilot in the wreckage of a helicopter Thursday that disappeared while doing a pipeline survey.

Iberia Parish Sheriff Louis Ackal did not release the pilot's name.

Ackal said the wreckage was found in the swamps of the Atchafalaya Basin, south of Baton Rouge, about 100 yards from the pipeline the pilot was flying over.

"The Federal Aviation Administration has been notified the crash involved a fatality and investigators are on their way to the scene," Ackal said.

Chief Criminal Deputy Sheriff Richard Hazelwood said the pilot of a state police helicopter spotted the wreck and directed authorities on the ground to the crash site.

"Rescuers used boats to get close to the site and then had to walk in 2 to 3 feet of water to reach the wreckage," Hazelwood said.

The helicopter disappeared Wednesday afternoon after leaving Gonzales, Louisiana.

"The aircraft was scheduled to refuel in Patterson, Louisiana, about 12:30 p.m., but never arrived," Hazelwood said.

The civil air patrol began a search for the overdue helicopter about 2 p.m. and "the Iberia Parish Sheriff's Office was notified about the missing aircraft about 7 p.m.," he said.

Deputies from neighboring St. Mary Parish, state wildlife personnel and the U.S. Coast Guard assisted in the search.

The helicopter is owned by Gulf Coast Helicopters, Inc., he said.

A call to the Pearland, Texas company by The Associated Press was not immediately returned.