Artist renderings of Jane Doe whose decapitated head was found in Western Pennsylvania is shown during a news conference in Economy Pennsylvania Thomson Reuters By Elizabeth Daley

ECONOMY, Pa. (Reuters) - Investigators said on Monday that red balls had been placed in the eye sockets of a woman’s embalmed head found a year ago in a case that may be linked to a growing black market for body parts.

Economy Borough Police Chief Michael O'Brien at a news conference appealed to the public for help identifying the woman, whose head was discovered in the woods by a child walking home in the rural town about 22 miles (35 km) northwest of Pittsburgh on Dec. 12, 2014.

Despite nearly 30 leads from the public following publication of artist renderings and a bust of the woman's head, she remains unidentified, police said. She was described as Caucasian and about age 50.

Beaver County District Attorney Anthony Berosh said an investigation is under way and it encompasses a range of possibilities.

"There's a black market on body parts and that market is pretty extensive," Berosh said.

O'Brien said the head was found too far off rural Mason Road to have ended up there accidentally and animals moving the head had been ruled out because the embalming fluid would have made it unappealing.

"It didn't roll off a truck. It just didn't happen that way," Berosh said.

Holding up a toy red rubber ball that was similar to those discovered in the woman's eye sockets, O'Brien said funeral home directors and medical examiners all told police that they "have never even heard of this type of use to replace eyes that have been enucleated from the body."

Beaver County Coroner Teri Tatalovich-Rossi said the head was severed with jagged cuts on the exterior, and more precise cuts on the interior. The time of death could not be determined due to the embalming fluid.

Toxicology reports indicate the woman had trace amounts of drugs used to treat cardiac distress in her system, suggesting she may have died from heart failure, O'Brien said.

New information from hair and tooth enamel indicates that in the seven months leading up to her death, she moved up to four times and possibly lived in southwestern Pennsylvania, central Pennsylvania, eastern Ohio, northern West Virginia, northern Maryland or eastern New York, O'Brien said. Her last dental work was likely performed in the 1990s.

O'Brien said the head was buried on Saturday after investigators had obtained all possible forensic evidence.

(Editing by Barbara Goldberg and Bill Trott)