The Cambridge Crown Court was informed that the girl was just 16 years old when her father sexually abused her for a month for getting a child for his new partner, who became infertile following a hysterectomy, the Daily Mail reported.
The girl, who gave birth to a baby boy in December 2008 and passed him off as the son of her ex-boyfriend, though she had never slept with him, finally told the police in March this year when she discovered her father making advances to a 14-year-old girl in the family home, the report said.
In a shocking police interview shown to the jury, the girl said, "He started pestering me. I said I did not want to have sex with him, but he locked the bedroom door. I knew it was illegal to have sex with your father. I said it's illegal and I do not want to get pregnant or get into trouble. That's how I got pregnant. He told me not to tell anyone."
The court heard that the teenager's father threatened to kill himself if she told anyone about the abuse. "He said he would take 1,000 tablets," she said. The girl and her father, both from Cambridgeshire, have not been named "for legal reasons".
The father denies three counts of rape, one of sexual activity with a child and one of sexual assault of a child.
A similar case took place in Austria where Josef Fritzl kept his daughter Elisabeth locked in a cellar for nearly 24 years and raped her numerous times.