CHICAGO (AFP) - The death of a young boy adopted from Russia at his Texas home was an accident and the bruises found on his body were self-inflicted, a coroner ruled in a case that ignited a diplomatic row.
Russian officials had claimed that three-year-old Max Shatto (born Maxim Kuzmin) was tortured and murdered by his adoptive mother, whipping up a storm of controversy less than two months after Russia banned US adoptions.
But four doctors who reviewed the autopsy results cleared his adoptive parents of wrongdoing, officials said in a statement.
The autopsy concluded that Max - whose mother found him unconscious in the backyard and rushed him to hospital - died from a lacerated artery in his bowel due to blunt force trauma in his abdomen.
"Based on all medical reasonable probability, the manner of death is accidental," the Ector County Medical Examiner's Office said.
While Russian officials accused Laura and Alan Shatto of doping the boy with "psychoactive drugs," the toxicology report found no drugs or medicines in his system.
The coroner also noted that Max Shatto had a mental disorder that caused him to hurt himself.
The Ector County Sheriff's Office said it would continue to investigate, along with other agencies.
"We are going to let this investigation take its course and do what is proper and right," the sheriff said.
While the Shattos are cleared of homicide, they could still face negligence charges for leaving the boy alone in the yard.
"They've taken care of the issue of willfulness, that's knowing and deliberate," the family's attorney, Michael Brown, told the Odessa American newspaper.
"They left open any issues of criminal negligence, which I don't think are there either."
The boy's death exacerbated diplomatic tensions triggered by a US bill targeting Russian officials with sanctions over the prison death of Russian lawyer Sergei Magnitsky.
Russia retaliated with a ban on all US adoptions, saying Russian children in the United States were abused and even murdered by their adoptive parents.