Subhan Anwar and his lover were jailed for killing her daughter, who suffered 107 injuries during a month of 'unbelievable' cruelty.
Two-year-old Sanam Navsarka had all her limbs broken, had been locked in a cupboard and was put in a tumble dryer.
Her mother Zahbeena Navsarka, 21, was cleared of murder but found guilty of manslaughter and jailed for nine years.
Navsarka's married lover Subhan Anwar, also 21, was jailed for life for murder and was told he would serve a minimum of 23 years.
In the witness box at Bradford Crown Court, in February 2009, the pair had blamed each other for Sanam's death.
Judge Peter Thornton QC summed up the toddler's ordeal by telling the court: 'Humanity has let her down.'
'It is almost unbelievable the pain and anguish she must have suffered, not just once or twice, but repeatedly and persistently over weeks at your cruel and selfish hands.'
Social workers from Kirklees Council in West Yorkshire met the couple and the girl three times during the period she was being systematically beaten to death, but had no idea what Sanam was enduring.
As well as putting her in the tumble dryer, Anwar dumped her in the bin as her mother looked on.
The court heard that tiny handprints and bloodstains were found inside cupboards at their home in Huddersfield and at a former property in Batley.
A post-mortem examination revealed her arms and legs were broken and there were 107 injuries across her body, including 36 bruises to her head and neck, 26 to her arms and ten to her abdomen.
Two 'tramline' bruises on her thigh showed where she had been battered with metal poles. And the toddler suffered further agony when aftershave was splashed over her nappy rash and open sores.
Not once did her mother take her to a doctor for treatment.
Eventually their failure to help Sanam killed her. Fat deposits from her broken bones entered the bloodstream and caused her death.