US ambassador to Russia Michael McFaul has warned against “the sensational exploitations of human tragedy” after Russian officials accused an American woman of murdering her adopted Russian son, Max Shatto.

Michael McFaul said the US had been working behind the scenes with Russian diplomats after Max Shatto’s death.

Three-year-old Max Shatto died in January. He was adopted from a Russian orphanage.

Officials and parliamentarians have regularly used the death to justify a recent ban on adoptions to America.

In a blog post on Friday, Michael McFaul said that he was “distressed about a number of issues surrounding the tragic death”, including the way that the US and its diplomats were being portrayed by some Russian commentators.

The ambassador said that “a thorough investigation to discover exactly what happened to Max was still under way” and that investigators are abiding by an important principle in American society: “the idea that one is innocent until proven guilty”.

Michael McFaul added that while he was “saddened and appalled” that 20 children adopted from Russia to the US over the last two decades had died, he was proud that more than 60,000 others “have had the opportunity to enjoy loving parents, new families, and countless opportunities in America”.

“It is time for sensational exploitations of human tragedy to end and for professional work between our two countries to grow, on this issue and many others,” Michael McFaul said.

Russian officials and parliamentarians have regularly used Max Shatto’s death to justify a recent ban on adoptions to America

News of Max Shatto’s death led to an angry reaction in Russia, where he was known as Maxim Kuzmin.

Outraged officials said that he may have been badly beaten and abused.

Russia’s top investigative body on Wednesday opened a murder inquiry into the case.

Earlier in the week, the Russian children’s commissioner went on Twitter to say that Max Shatto had been murdered by his adoptive mother Laura Shatto.

Russia banned adoptions to the US from the beginning of January in retaliation for an American law know as the Magnitsky Act – which blacklists Russian officials accused of rights abuses.

The US act was named after anti-corruption lawyer Sergei Magnitsky, whose death in Russian custody became a symbol of the fight against corruption in Russia and soured relations between the two countries.

Some 3,400 Russian children were adopted by foreign families in 2011, with almost a third of the children going to American homes.

In the past two decades, Americans have adopted more than 60,000 Russian children.

[youtube 45fdLtnkgRg]