Sheriff Ivy Woods said Monday, a preliminary autopsy revealed no immediate sign of trauma or what caused the woman's death.
Authorities are now awaiting toxicology results from blood and tissue tests, which could take several weeks.
Authorities are continuing to treat the case as a suspicious death until an official cause of death can be determined, Woods said.
The body of 27-year-old Lacie Fontenot was found lying face down in a shallow ditch in a small wooded thicket in a residential area on Sixth Street between Commercial Avenue and New Orleans Street in Lake Arthur.
The body was spotted around 3 p.m. by another woman walking along an old railroad track on the town's west side.
Lake Arthur Police Chief Cheryl Vincent said Fontenot had not been seen in nearly a week, but had not been reported missing.
Anyone with information on Fontenot's recent activities should contact the Lake Arthur Police Department at 774-2411 or the Jeff Davis Parish Sheriff's Office at 824-3850.