The son of the man referred to as the "British Fritzl," who fathered nine children by raping his two daughters, disclosed today that he had reported the matter to police and social services more than a decade ago but no action was taken.

The man, who did not want to be identified, said that he had lived in terror because of the abuse he, his mother and his sisters faced when he was a child in Lincolnshire and South Yorkshire, claiming he still has 49 scars on his head from the beatings he suffered.

The father, 56, was last month sentenced to a life term for a total of 25 rapes and will serve 19-and-a-half years. Sheffield Crown Court heard that his rapes had caused his daughters to get pregnant a total of 19 times.

He held his daughters virtual prisoners for 25 years, the court was told, moving them around houses in South Yorkshire and Lincolnshire to avoid detection.

Speaking for the first time about the ordeal on BBC Radio 5 Live, the son said that he had lived in terror of repeated beatings and torture until he left home at the age of 15.

However, he said did not know about his father's incestuous rapes with his sisters — and who fathered the children which resulted — until having a conversation with his mother, who at that stage had also left home, at the age of 18.

He said he told police, who reported the matter to social services — but nothing was done after he was interviewed by social workers.

"I thought it would all be taken care of — you know, when an allegation like that's put forward you'd think they'd investigate it, wouldn't you. But somehow nothing's ever got done," he said.

Lincolnshire Police and Lincolnshire Safeguarding Children Board said they were investigating what happened to the family and how their circumstances were dealt with. They said they would not comment until the investigation was completed.

Click here to read more on this story from The Times of London.