The remains of a 3-year-old boy who died after his foster parents bound him in a blanket and packing tape and left him in a closet have yet to be claimed and buried, a prosecutor says.

Marcus Fiesel's biological mother, Donna Trevino, turned down an offer for a private burial that was made by Hamilton County Prosecutor Joe Deters two weeks ago and told him she would make arrangements herself.

Since then, however, nothing has been done. In a letter to Trevino on Friday, Deters said he understood her decision. "What I cannot understand is your failure to claim Marcus' remains and put him to rest."

Deters' letter is political, said Kevin Hughes, a lawyer who represented Trevino in a lawsuit over her son's death.

"This woman has wanted to bury (Marcus) from day one," Hughes said.

Marcus, who was developmentally disabled, died after foster parents Liz Carroll and David Carroll Jr. left him in the closet in their Cincinnati-area home for two days while they attended a family reunion in Kentucky in August.

Hughes said he would work on burial arrangements with Butler County, which agreed to pay for funeral services because Marcus died while a ward of that county. Burial there would be more convenient than Hamilton County because Trevino does not drive and it would be easier for her to visit the grave, Hughes said.

Deters said the boy's remains, salvaged from a chimney where investigators say his body was burned, are so few that they could fit inside a Dixie cup. Investigators say most of his ashes had been dumped into the Ohio River. The rest are being kept at the county coroner's office in a special cooler to prevent decay.

Liz Carroll, 31, was convicted of murder and other charges in February and was sentenced to at least 54 years in prison. Her husband, 29, accepted a deal in which he pleaded guilty to murder and gross abuse of a corpse and was sentenced to serve at least 16 years in prison.