Little Artem Saveliev was last year taken from a grim orphanage and given a new life in Tennessee last year.
But his adoptive mother Torry-Ann Hansen, a 34-year-old nurse, yesterday put him on a ten-hour flight as an unaccompanied minor with a note 'to whom it may concern' saying: 'I no longer wish to parent this child'.
In his rucksack, she had placed sweets, biscuits and colouring pens for the journey.
She did not tell him she was rejecting him. Instead, she and a grandmother that he was going on an 'excursion' to Moscow.
In the typed note, which the blond boy was clutching when Moscow police picked him up, she said she wanted the adoption annulled.
She accused the Vladivostok orphanage of misleading her about the child's behavioural problems.
The Russians angrily denied this, saying he was stubborn but that his only disability was that he was 'flat-footed'.
Officials said they have never witnessed such cruelty to a child after promising a 'new life'.
Unwanted Artem, eight next week, looked confused and bewildered as he was taken into care by Moscow social services.
The Kremlin's children's rights commissioner Pavel Astakhov lambasted the U.S. mother, who is understood to be a nurse and a single parent with a natural son.
Russia's foreign minister is now demanding a freeze on adoptions between the U.S. and Russia.
Foreign Minister Sergey Lavrov was quoted by Russian news agencies as saying the ministry would recommend that the U.S. and Russia hammer out an agreement before any new adoptions are allowed.
'We have taken the decision ... to suggest a freeze on any adoptions to American families until Russia and the USA sign an international agreement' on the conditions for adoptions and the obligations of host families, Lavrov was quoted as saying.
He also said he was 'indignant' at the way the child was treated 'as a parcel'.
Lavrov said the U.S. had refused to negotiate such an accord in the past but 'the recent event was the last straw'.
U.S. ambassador to Russia, John Beyrle, said he was 'deeply shocked by the news' and 'very angry that any family would act so callously toward a child that they had legally adopted'.
Russian officials also refused the U.S. consul access to the child saying: 'If his American parent kicked out him from the country on a plane like a sack of potatoes, then we will look after the boy.
'Our care system will take up the case. After a full medical examination, he will be placed into one of our orphanages.'
Ashtakhov questioned how American immigration had let the child leave Washington, and why United Airlines had carried him alone to Moscow. Normally, stringent checks are applied on minors travelling without parents.
It appears the child was also alone when he flew from Tennessee to Washington before boarding the flight to Moscow.
'The adoptive mother broke all the rules and procedures by sending an adopted child back,' he said.
Ashtakhov, who said he played with the child and talked to him, said the mother had another son called Logan.
'Artem said he made good friends with Logan,' he said. 'He was talking quite calmly about the family, but when he started to talk about his mother he began to cry, showing how she dragged him by the hair.'
In a shocking typed letter she gave to her seven-year-old 'son' to take with him to Moscow, she revealed how she adopted the boy in September 2009.
She claimed he is 'mentally unstable' and that his problems were hidden from her by Russian orphanage officials before she adopted him.
'He is violent and has severe psychopathic issues/behaviour. I was lied to and misled by the Russian orphanage workers and director regarding his mental stability,' she wrote.
'They chose to grossly misrepresent those problems in order to get him out of their orphanage.'
The letter - addressed 'to whom it may concern' at the Russian Ministry of Education in Moscow - said: 'After giving my best to this child I am sorry to say that for the sake of my family, friends and myself, I no longer wish to parent this child.
'As he is a Russian national, I am returning him to your guardianship and would like the adoption disannulled.'
Adoption officials in Partizansk, near Vladivostok were stunned, saying that the U.S. woman had made a good impression on them when she went through adoption procedures last year.
She spent four full days with Artem watched by adoption workers before she was allowed to become his mother.
'It was clear that there was mutual affection, and it was good,' said Vera Kuznetsova, chief adoption officer in the region.
'She seemed a nice, kind woman. Artem immediately reached out to her. She even learned a few Russian words to communicate with her future son,' said one official.
U.S. social workers also submitted reports on Hansen for the court which granted the adoption. 'They did not doubt Hansen's honesty and sense of responsibility,' she said.
Recent follow-up reports from America on the boy did not detect any strains in the family, it is claimed.
Russian officals deny Hansen's claims about Artem having severe behavioural problems and being mentally unstable.
'Artem is normal for his age,' said the official. 'He is a little stubborn child, but this is not a problem for loving parents.
'We are shocked by how the American family has treated our child. Artem grew up as a completely normal, relatively advanced child for his age, and healthy. Does she count being flatfooted as a disability?
'No other medical abnormalities were found. The child was completely ready for school (Russian pupils start school at seven years of age) and had learned to read when the American mother came to the orphanage.'
American psychotherapist Joe Soll told Russian media that the boy's rejection from his adopted family would have a serious impact.
'When you remove a child from a family, no matter what the circumstances are, it's a trauma,' he said.
'We don't look at children who have been adopted as tramuatised, but they are. I don't think people are educated at all to understand what adoption is really about.'
The child's real mother Ekaterina was deprived of her parental rights because she was an alcoholic, officials said yesterday.
She gave birth to the child at 19 and cared for him until he was six.
He was adopted by Hansen on 18 September 2009 in Russia and eleven days later she formally changed his name to Artem Justin Hansen.
Astakhov said the boy told him that neither he nor Logan went to school, but played at home in America. The boy spoke of a grandmother who shouted at him.
Russian officials believe it is this grandmother who actually organised the one-way trip to Moscow for Artem.
'Artem is a very nice kid. We drew pictures together and had nice chat,' said Astakhov.
Officials say they want action against the mother for child abuse. The Moscow media angrily denounced the 'cruelty' inflicted on the seven-year-old.
This shocking return of an unwanted child follows several appalling cases of Russian children being killed after being adopted to America.
In one case, a two-year-old boy died after his American father left him alone in a car in 30C temperatures.
The cases led to a public outcry and new curbs on adoption.
The case was highlighted on a day when U.S. President Barack Obama and Russian leader Dmitry Medvedev signed an historic nuclear arm reduction treaty in Prague.