Russia was seriously alarmed by the fate of an adopted Russian child in the United States to whom Russian consulate workers were being denied access, a high-ranking diplomat said Wednesday.

"We are seriously concerned with the situation of Russian child Yegor Shatabalov, adopted by the U.S. citizen Marcia Anne Brandt in 2007 under a ruling issued by the Kemerovo regional court," the Russian Foreign Ministry's envoy for human rights, democracy and supremacy of law, Konstantin Dolgov, said in an online comment.

According to Dolgov, Brandt had been in a same-sex marriage with another woman, Beth Chapman, before 2009. After their break-up, the two women became locked in a custody battle for the boy, who lives in San Francisco.

The custody dispute had become unacceptable and harmed the boy's psychological well-being, Dolgov said, adding Moscow believed the current circumstances were against the boy's best interests as the child needed bringing up in a normal family.

The Russian Foreign Ministry had been studying the circumstances of Yegor's adoption, the official said.

Dolgov said Brandt had concealed her same-sex union when she applied for adoption to bypass the Russian Family Code, which clearly described marriage as a union between a man and a woman.

On Feb. 13, Dolgov demanded access to Shatabalov, but the diplomat did not reveal the boy's name at that time.

On Monday, Russia called on U.S. authorities to punish the adoptive mother of a Russia-born boy who died allegedly due to her criminal negligence.

On Feb. 9, President Vladimir Putin said Russian orphans should be adopted in their homeland.

The conditions for Russian children in U.S. families became a hot issue at the end of 2012 when Moscow passed the Dima Yakovlev Act, or the so-called Anti-Magnitsky Act.

The act banned Americans from adopting Russian orphans in a tit-for-tat response to the U.S. Magnitsky Act.

The U.S. act, passed in December 2012, introduced a blacklist of Russian officials allegedly linked to the death of Russian lawyer Sergei Magnitsky in a Russian prison in 2009.