An eight-year-old boy had to have buckwheat surgically removed from his knees after his stepfather forced him to kneel on a pile of grain seeds in Russia.

Sergey Kazakov, 35, punished the boy for coming home late by making him kneel for nine hours at a time on the grain, causing seeds to take root in his bloodied knees.

The crop had to be surgically removed under general anaesthetic at a hospital in Omsk, Russia.

Kazakov also kicked the boy and pulled his hair while he was kneeling and the boy's mother Alina Yumasheva admitted she had approved the punishment.

Injuries: Buckwheat took root in an eight-year-old boy's knees (pictured) after he was forced to kneel on grain seeds for nine hours at a time by his stepfather

Suspects: The boy's mother Alina Yumasheva (pictured left with her son) said she had approved the punishment delivered by her partner Sergey Kazakov (right)

Yumasheva claimed that she and Kazakov discovered the form of punishment on the internet.

The mother told the newspaper Komsomolskaya Pravda: 'I checked on it myself and set up an experiment.

'I knelt on it. It didn't hurt me. So he (Kazakov) was allowed to apply this punishment.'

However, sources said the boy was forced to kneel on grains which were like 'rough sandpaper' and he was heard crying 'it hurts' as he was kicked by his stepfather.

The couple also starved the boy for up to four days at a time, claim state investigators.

Kazakov told police he had inflicted the punishment once but several more deleted videos were traced on his phone, say investigators.

'Punishment': The boy's stepfather punished him for coming home late by making him kneel for nine hours at a time, leading grain seeds to take root in his bloodied knees

Accused: Yumasheva (pictured in court) and Kazakov, a computer programming entrepreneur, are now facing trial in Omsk

The boy's ordeal came to light when he fled the family home and pleaded with a female neighbour to help.

She called in doctors because of the horrific wounds on the child's knees from which blood was flowing.

Kazakov, a computer programming entrepreneur, and Yumasheva are now facing trial in Omsk.

The couple are under investigation for torture, causing damage to the boy's health, and failure to properly educate the boy.

He was remanded in custody and she was barred from leaving her home pending criminal investigations.

Victim: The boy (pictured) had to have the buckwheat surgically removed from his knees under general anaesthetic at a hospital in Omsk, Russia

Kazakov (pictured) told police he had inflicted the punishment once but several more deleted videos were traced on his phone, say investigators

However, after one month in hospital, the boy has been returned into her care, say Russian reports.

This was despite the boy pleading with his nurse in hospital: 'Will you send me to live in a good family now?'

The child's class teacher Olga Pidzhakova said the boy was academically bright but she believed he had been scared to complain.

'He is a good, positive child,' she said. 'His mother constantly attends parental meetings, comes if I call.

'He is always clean, and neatly dressed.

'Neither I, nor other teachers or children were even aware that he was being bullied at home. It is only now that I find out he was simply afraid to complain to us.'