A Leeds carer, who got a severely disabled woman pregnant by raping her when he was supposed to be looking after her has been jailed for 15 years.
Edson Munyikwa, 55, preyed on the victim when he was supposed to be providing respite care for her.
A judge described the offence carried out by Munyikwa as "hideous" as he gave him the extended prison sentence.
Blood samples were taken and showed that she was three months pregnant.
Leeds Crown Court heard the victim had to undergo an abortion and was left seriously traumatised as she did not understand what had happened to her.
The woman, who suffers from a range of serious disabilities including brain damage, epilepsy and autism means she is unable to speak or communicate.
Procesutor Deborah Smithies, told the court that the victim did not have the capacity to consent to sex.
The crime came to light when it was noticed that she had missed her period and the epileptic fits she was having were becoming worse.
Miss Smithies said a police investigation was launched to trace all men who had been in contact with her.
The woman's father was also placed under suspicion the court heard.
He volunteered to give a DNA sample so he could be eliminated as a suspect.
Munyikwa gave a DNA sample after he was identified as being in contact with the woman. The defendant's work colleagues were also placed under suspicion.
Munyikwa was arrested at his home in Rothwell, Leeds, after he was identified as being the biological father.
He denied having sex with the woman when he was interviewed.
The prosecutor said: "When asked how he could be linked specifically to the product of conception he said that he did not know."
Munyikwa, of High Ridge Avenue, Rothwell, Leeds, pleaded guilty to rape.
Miss Smithies read statements to the court on behalf of the victim's relatives.
The family described the severe trauma and anxiety suffered by the woman as a result of Munyikwa's offending.
One statement read: "She was targeted because of her vulnerability and her inability to communicate.
A probation officer who interviewed Munyikwa described in a report how the defendant "lacked a heartfelt expression of remorse" for what he had done.
Munyikwa, who is originally from Zimbabwe has no previous convictions in the UK and no record of him offending in his home country.
Judge Khokhar told Munyikwa he was imposing an extended prison sentence as he considered him to pose a serious risk to the public.
Mr Munyikwa will serve a custodial term of 12 years followed by an extended three-year period on licence.
The Judge told Munyikwa: "You committed a very serious and hideous offence."
"This is probably the worst case of its type I have come across.
"One finds it difficult to understand why someone like you would, out of the blue, go and commit an offence of this type.
"There is no explanation other than what you told the probation officer.
"That has not been delved into in detail to find out what is behind it."
The Judge told Munyikwa he had undermined the public's confidence in his profession and had placed others under suspicion.
He said that his victim would not have appreciated at the time what was happening to her and that Munyokwa was in the secure knowledge of her not being able to communicate what he had done with her to anybody else.
"There could be no greater torment for a father than to be accused of having sex with his own child.
"He had to live away from her until he was eliminated from the enquiry.
"Similarly, those who work with you at your workplace were subjected to suspicion and suspension.
The judge also described how his colleagues had suffered a great deal of embarrassment and torment in front of their families and friends because of it.
Munyikwa pleaded guilty and apologised to his victim and her family.