A Tennessee preacher who advocates doses of physical pain as the best strategy for keeping wayward offspring in check -- a swipe from a length of plastic plumbing tubing works well, he suggests -- is coming under scrutiny after his teachings have been linked to the deaths of three children in the US.

Michael Pearl, pastor of the No Greater Joy ministry church at Cane Creek in Pleasantville, has garnered a following of Christian parents across the country who take guidance on corporal punishment from his book, 'To Train up a Child'.

He first self-published it in 1994 and to date has sold nearly 700,000 copies.

The pressure on Mr Pearl to explain his child-rearing philosophy grew further yesterday with a front-page article in 'The New York Times' detailing three cases of children dying, allegedly after extreme abuse by parents who were disciples of his teaching.

The teachings of Mr Pearl (66) first came under the microscope after a North Carolina mother, Lynn Paddock, was convicted in the suffocation death of her young son, Sean, in 2006. At the trial, some of her other children testified they had regularly been beaten with plumbers' tubing as Mr Pearl had recommended.

The pastor insists that his book makes clear that spanking of children must never be taken to extremes. If parents ignore this, it makes no sense to blame him, or his book.

While the surfacing of two more cases where children have died from abuse in homes that apparently adhered to his methods will put additional pressure on Mr Pearl, it will also reignite a debate in the US about the use of corporal punishment on children.