Gold-toothed Viktor Lishavsky, 37, abused the children for whom he was the legal guardian.
A Russian paedophile who committed more than 900 rapes and sexual attacks on five underage schoolgirls in his care has been jailed for 22 years and six months.
Gold-toothed Viktor Lishavsky, 37, abused the children for whom he was the legal guardian, treating them as his "personal harem" and "sexual slaves".
The stepfather admitted his guilt to all charges - but refused to give evidence at his closed-door trial in Komsomolsk-on-Amur in far east Russia, the Daily Mail reports.
The former head of an evangelical church in the town of Amursk, he is believed to be the worst convicted paedophile in Russian history.
A court in Komsomolsk-on-Amur found the "monster" guilty of more than 900 counts of rape and violent sexual acts mostly against girls aged 13 in his care.
He will serve his sentence in a "strict regime" penal colony, after which he will face another two years unable to leave the town where he lives and reporting regularly to police.
He was banned from working with children for a further two decades after his release.
Lishavsky was caught after a five year reign of sexual terror when one of the girls confided in her foster mother Olga who had been entirely unaware of his abuse, the judge was told.
Other victims then corroborated the accusations against him.
By day he ran a shoe repair shop but at night he regularly attacked the adolescent girls in his care.
Lishavsky and his wife had three children of their own and fostered nine more.
He was found guilty of the rape of minors, including acts committed with "particular cruelty", and forcing his underage victims to commit acts of a sexual nature using the children's material dependency on him as a foster father, according to a statement from the court.
He was also convicted of indecent acts without using violence against girls under 16 years old, and "torture".
Further he was found guilty of improper performance of responsibilities for raising a minor along with the cruel treatment with a minor.
State prosecutor Tatyana Filatova said: "None of the girls complained because each considered him a father.
"Some told each other about what had happened, but they were not in a hurry to complain to their mother.
"The children were taken from an orphanage, and none of them wanted to lose their family.
"They finally had both a mum and dad. The terrible details came to the surface only later.
"After discussing everything among themselves, one of the girls said that she was not afraid of her father - and would tell everything to her foster mother.
"The mother, in turn, went to the police."
The prosecutor said: "All these years, the adoptive mother did not see anything, because she often was in hospital with her son.
"In court, they tried not to go deep into the details of the crimes in order not further harm the victims."
The hearing was held behind closed doors but a charge sheet showed he had been accused of 248 rapes plus 358 "violent sexual acts" against girls aged 13 or under.
He faced another 22 accusations "violent acts of a sexual nature" against girls below the age of 14.
Lishavsky committed a further 11 rapes or other brutal sexual attacks in which he threatened murder or serious harm to health, the court was told.
These involved "particular cruelty", according to the charges.
Several other charges relate to torturing the girls and abusing his role as a guardian.
Separately, Lishavsky was accused of a further 122 crimes of "a sexual nature with the use of violence, or threat of violence", and 151 charges of "sexual intercourse taking advantage of the helpless state of the victim" - all these against underage girls between 14 and 17, according to Russian media reports of the case.
He "considered the girls to be his personal harem," according to a report by Ren TV.
One newspaper branded him a "paedophile sex monster".
"With the money that the government paid him as a foster parent, he rented an apartment where he had sex with either one or another foster daughter every other day, or every third day."
The man was paid £265 a month by the state to care for each of the five adolescent girls he abused.
Officials in the Khabarovsk region of eastern Russia are said to be 'deeply shocked' over the allegations against a man they viewed as a "model foster father".
The court heard that he was thought to be "respectable".
Alla Kuznetsova, education minister in the region, said the foster parents had passed repeated inspections by social services.
"In the case of this family, there were no alarms at all," she said.