New Orleans police have launched a homicide investigation after a man's body was found in a garbage can on St. Ann Street in Treme.

A garbage collector discovered the man's body about 9:30 a.m. while emptying a city-issued trash can into the back of a garbage truck, stopped in the 2100 block of St. Ann, NOPD spokeswoman Dawne Massey said. The cause of death remains unknown, Massey said. Homicide detectives, including the head of that unit, were called to assist in the department's investigation.

The department initially called the investigation an "unclassified death," but later said via Twitter that the investigation had been classified as a homicide. The department did not provide an explanation for the reclassification.

Police later announced that the signal had been classified more specifically as a "homicide by cutting" after stab wounds were found on the man.

Officers used yellow police tape to cordon off the 2100 block of St. Ann, while investigators focused their attention on a green garbage truck stopped in the middle of the street. The trash can was hoisted in the air, lifted by a piece of equipment attached to the back of the truck. It remained in that position, tipped halfway over, as authorities peered their heads into the back of the truck.

About an hour after police roped off the crime scene, officers pushed back the edge of the scene to include the intersection of St. Ann and North Johnson streets. About five people gathered near that corner, while a larger crowd of a dozen or more people stood on the other side of the crime scene, watching officers work from the corner of St. Ann and North Galvez.

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A man wearing a brightly colored vest who had been talking to police inside the crime tape later told a reporter he was the garbage collector who found the body. The 41-year-old man, who asked not to be identified by name, said he remarked aloud how heavy the trash can felt when he first picked it up.

It wasn't until the can tipped over into the garbage truck, the garbage collector said, that he saw a man's body pour out of it. There was blood pooled in one corner of the bottom of the can, the garbage collector said.

"He had his hands over his face," said the garbage collector, who scrunched up his arms and a leg toward his torso to demonstrate the man's position, describing a rigid fetal position.

The garbage collector said he's held that job for eight years and had seen a dead body before -- but not close up, and never on the job.

A woman on a porch near St. Ann and North Galvez streets said she heard the garbage collector yelling as he picked up trash on the block.

"When he emptied (a can) he went to hollering," said the woman, who asked not to be identified.

The woman said the garbage collector ran around to the front of the truck as he yelled, alerting the driver about what he found.

The garbage collector acknowledged he yelled once he discovered the body.

"I ain't never been that close to something like that," he said. "That's like, a real reality check there."

Another woman standing near the corner of St. Ann and North Galvez looked at the crime scene from behind the tape and said of the garbage collector, "That young boy probably traumatized."

Staff photographer Michael DeMocker contributed to this story.

This story has been updated with additional information.