London, Nov 30 : The son of "British Josef Fritzl" was told by his mother that he can win his father's affection only if he 'gets his sex changed'.
Now in his 30s, the son has for the first time revealed the horror he and his two sisters went through in their years of hell with their evil father.
The father, who was last week given 25 life sentences, had abused his daughters over a period of at least 25 years, fathering nine children with two dying at birth.
The case bears stark similarities to that of Austrian sex beast Josef Fritzl, who kept his daughter as a sex slave in a dungeon for 24 years and fathered seven children by her.
The son of the 56-year-old businessman revealed how he and his two sisters were beaten and abused while the girls were regularly raped.
The girls were made pregnant 19 times and the three siblings were made to eat disgusting raw offal and were viciously battered when they refused it.
They were even banned from using the toilet at night and kept prisoner in bedrooms secured with special locks, which went with them when they moved home every few months.
The son, who cannot be named, realised as a tiny lad that his father was more violent to him than to the girls.
But when he asked his mother, who fled home before he was ten, how he could win his dad's affection she gave him shocking advice.
"She said to me, 'The only way you'll get on with your father is if you have a sex change," News Of The World quoted the son as saying.
He added: "I was only little and didn't know what she meant. But I did know he treated the girls much nicer than me - although he would beat them up too, and my mum."
But, he did not realise at the time that the apparently less harsh treatment was because his sisters were being kept as sex slaves.
The son, who attempted suicide at seven, even had to sleep in a cupboard in one of the houses they moved into.
The father kept all three of his children strictly under lock and key.
He said: "Everywhere we went, he took those locks with him and put them on the girls' doors to stop them getting out at night. He didn't need the locks because we were so in fear of him we didn't dare leave our rooms.
"We were banned from going to the loo at night and we each had a bowl or a bucket to use. Our childhood was so terrible, so many beatings, that most of it is just a painful blur."
The family moved house up to 30 times throughout South Yorkshire and Lincolnshire to stop authorities becoming suspicious.
The children were so scared they never even spoke to each other about their sufferings.
The brother finally came to know of the abuse to his sisters in the 1990s when he was 18.
He has now come out in open to speak only after the father was caged at Sheffield Crown Court for raping his daughters hundreds of times over 30 years.
Now, the son is on permanent medication to cope with mental problems caused by his hideous childhood.