US-Russian adoptee Max Shatto 'playing before he died'
The US adoptive mother of Russian-born Max Shatto says the dead three-year-old was playing outside before she found him unresponsive, Texas officials say.
Russia's top investigative body has opened a murder inquiry into the case, which comes after Russia banned US adoptions, citing previous deaths.
Max Shatto - whose Russian name is Maxim Kuzmin - died on 21 January.
Texas officials say they are still investigating the death, and no arrests have been made.
Max Shatto and his two-year-old brother Kristopher were adopted from an orphanage in north-western Russia last year by Alan and Laura Shatto, who live in Gardendale, Texas.
They have not commented publicly on the case.
Laura Shatto told deputies that the two boys had been playing outside together before she left the house and found Max on the ground, Ector County Sheriff Mark Donaldson said.
Deputies arrived at the home as the ambulance was leaving with Max, he said, and the boy was pronounced dead at the hospital a short time later.
Forensic investigator Sondra Woolf said bruises had been found on Max's body, but it was not immediately possible to say whether they were related to the cause of his death. An autopsy is being conducted.
The US state department has said it will help Russian officials make contact with the appropriate authorities in Texas.
"It is a terrible tragedy that this child has died. But none of us, not here, not anywhere in the world, should jump to a conclusion about the circumstances until the police have had a chance to investigate," the state department's Victoria Nuland said on Tuesday.
The boy's death came just three weeks after the Russian parliament, the Duma, enacted legislation ending all adoptions of Russian orphans by Americans.
The move was criticised by the United States and by the opposition in Moscow, and was part of a Russian law passed to retaliate against US legislation which blacklists Russian officials accused of rights abuses.
In the past two decades, Americans have adopted more than 60,000 Russian children.
The deaths of 19 of them in the past 10 years have raised concerns in Russia, particularly the 2008 death of Dima Yakovlev, known in America as Chase Harrison, who died of heatstroke after his adoptive father left him in a car on a hot day.
Miles Harrison was acquitted of his manslaughter at trial.