Russian authorities will investigate how Samuel and Donna Merryman who were charged with murder of the Russian stepson, adopted the 8-year old.
U.S. prosecutors have charged the Merrymanans, of Harford County, Maryland, with murdering their son Dennis, who they adopted in Russia five years ago, The Russian Embassy in Washington was quoted as telling ITAR-Tass and RIA-Novosti news agencies.
The statement came amid a wave of concern in Russia about the fate of Russian-born children adopted by American parents following a series of abuse cases that has prompted a senior Russian lawmaker to call on halting adoptions by U.S. citizens.
The 8-year-old boy died in January and an autopsy report said starvation was the cause of death, according to The Baltimore Sun. The Merrymans deny the report, saying the child died of an illness.
Prosecutors said they will look into the legality of the 2000 adoption of Dennis Uritsky and three siblings in the Ural Mountains city of Perm.
Dennis Merryman was the 13th Russian-born child to die in the United States after being adopted by American parents since Russia allowed foreign adoptions in the early 1990s, prosecutors said.
Some 260,000 Russian orphans are awaiting adoption in cash-strapped children's homes where educational opportunities and medical care are limited. Homes are found for about 15,000 children annually, with about half of them outside Russia and most of those by U.S citizens.
Russians rarely adopt, in part because of social stigma, and nationalists often accuse foreigners of "buying" Russian children and cases of abuse are widely reported in the Russian media. Rights groups, however, point out that hundreds of children are killed in Russian families each year.
A recent Public Opinion Foundation poll showed 62 percent of respondents were in favor of tightening adoption rules for foreigners. Answering a different question, 39 percent of respondents favored forbidding foreign adoptions altogether. The poll interviewed 1,500 people and its margin of error was 3.6 percentage points, the AP reports.