The Wake County Sheriff's Office said the body was located around 11 a.m. in the 5400 block of Allen Drive, off of Old Milburnie Road near the Neuse River. The discovery came after deputies received a call from the Raleigh Police Department, which said a witness reported a body near the shoreline off the Neuse River Trail.
"It's not every day, it's not every morning that you find what could be a person's body in a suitcase, in a river," Wake County Sheriff Gerald Baker said Monday afternoon.
WATCH: Sheriff Baker's full media briefing
Law enforcement said it is working to identify the body at this time but Baker said at a media briefing that they had not yet confirmed the identity of the body.
"We're getting ready to confirm it," Baker said. "I can't sit here and tell you that's what's in there right now. We have not gotten to that point. We have information to believe it."
Authorities are awaiting the results of an autopsy by the State Medical Examiner's Office.
Baker said it was "safe to say this was no accident."
The family of a missing woman was at the scene.
On Thursday, the Wake County Sheriff's Office requested assistance in locating 28-year-old Brittany Samone Smith.
"We're going to work very hard. We're going to find out who was responsible. I can tell you that," Baker said. "Because these things just don't happen. Someone is responsible. If this is in fact, this young lady that we've been looking for all weekend, someone is responsible for that."
Smith was last seen Tuesday around the 200 block of Fox Run Drive, in Wendell. She may have also been seen in the 7000 block of Hodge Road.
Smith is approximately 4'11" and weighs around 115 pounds and is noticeably pregnant.
The Wake County Sheriff's Office is requesting the public's assistance with this investigation and asks anyone with information to call (919) 856-6911.