GALVESTON, Texas – A boy whose body washed up on a Galveston beach last year is still unidentified and investigators are still unsure of how he died, authorities said Tuesday.

Galveston police said investigators have exhausted hundreds of leads about the identity of the 3- to 4-year-old boy, who investigators called “Little Jacob.” The boy’s naked body was found Oct. 20 by someone walking on the beach near 7th Street and Seawall Boulevard.

DNA tests have also been unsuccessful, police said.

RELATED: Dateline NBC story about "Little Jacob"

In an effort to identify the child, investigators went to the drastic measure of releasing a photo of the boy’s face. Investigators said the image had been altered slightly to compensate for signs of decomposition and water damage.

WARNING: Some may find the photo at the following link disturbing.

PHOTO: Image released of "Little Jacob"

“We are not releasing this photo lightly,” said Capt. Joshua Schiarad, of the Galveston Police Department. “It’s really being done, at this point, as a last option.”

Police said an autopsy revealed that the boy likely died either Oct. 17 or Oct. 18. His body was placed in the water east of where he was found in the Galveston County area and was washed west to where he was found, police said. The boy had been in the water for between 12 and 48 hours, police said.

WARNING: Some may find the photo in the video at the following link disturbing.

VIDEO: Police discuss case of "Little Jacob"

Investigators said that the boy’s body showed signs of neglect and abuse, but none of those injuries appeared to be fatal.

“Input from the public is absolutely crucial,” Schiarard said.

Anyone with information about the boy’s identity was asked to call 800-225-5324.

Detective Jeff Banks of the Galveston Police Department said, "It's extremely frustrating. It's challenging to know you're a detective. You want to solve the case. Well where do you go when no one is telling you what's happening?”

A $10,000 reward is being offered for information that leads to the identification of the boy and the location of the child’s next of kin.