A man who forced a young girl to run barefoot on a treadmill for up to four-and-a-half hours so she would sleep at bedtime has been found guilty of child cruelty.
Garth Gatland, 39, of Austin Road, Cambridge, was convicted of two counts of child cruelty at Cambridge Crown Court on Thursday, Cambridgeshire Police said.
He had denied the charges against two children, a girl aged six and a 15-year-old boy.
The court heard that Gatland also hit the girl with a wooden spoon, made her stand naked in a window, subjected her to water boarding, made her stand in stress positions and tipped her out of her bed while she was sleeping on regular occasions.
Evidence of cocaine was discovered in the girl's system, and significant bruises and burns were found on her back, legs, feet and neck.
The boy was the victim of regular assaults and made to dispose of and hide drugs for Gatland.
The abuse, said to have happened between 2014 and 2016, was reported to police by an acquaintance of Gatland last year.
Detective Constable Chris Down said: "Gatland subjected his victims to a catalogue of sadistic abuse.
"I hope his conviction will allow the victims to move on with their lives.
"I would encourage anyone who suspects offences have been, or are being committed against children to report their concerns to police, children's social services or the NSPCC.
"No matter who we are, we all have a responsibility to report child abuse."
Gatland will be sentenced on a date to be fixed.
Co-defendant Marie Maltby, 32, also of Austin Drive, Cambridge, was acquitted on both counts.