The son of Fred Phelps, the pastor of Westboro Baptist Church, has claimed that his father beat his family until they bled.

Nate Phelps, who has been estranged from his family for more than 30 years, is writing a book about his experiences growing up in the Kansas church.

The church believes that soldier deaths abroad are caused by God as a punishment for America’s tolerance of homosexuality. It regularly pickets soldiers’ funerals with placards declaring ‘God hates fags’.

Speaking to HLN’s Issues with Jane Velez-Mitchell, Phelps, who is the family’s seventh son of 13 children, claimed his father abused his children and wife.

He said: “He used his fists. He used his knees and he used … the handle of a mattock [a pick-like digging tool]. He used that in such a way that it split the skin on the back of the kid’s legs so they bled.”

“If they want to call that discipline, that’s fine. But I call it abuse,” Phelps said. He also said that Fred Phelps beat his wife, although not with the mattock.

His sister, Westboro spokeswoman Shirley Phelps-Roper, refuted the claims as “lies”.

She said: “Nothing he can say will change the fact that God hates [homosexuals] and their enablers and therefore God hates America and America is doomed.”

Phelps, who responded that his sister was lying, added: “My father can make any connection to anything that anyone has done or hasn’t done in their life and point to that to say that that’s evidence they’re damned and going to hell.

“He’s convinced that homosexuality is the ultimate sin against God.”