The father of ten-year-old Tamar Stitt - who died from cancer after she was given treatment with mud rather than chemotherapy - has claimed he himself was treated for various ailments by clay sourced from hills south of Perth.
Trevor Stitt, who is a trained anaesthetist, was today called to give evidence in the inquest of Tamar, who died in 2009 in El Salvador.
She was taken there by her parents after health authorities began legal action to force them to agree to chemotherapy, after resisting the treatment for a massive tumour in the ten year-old's liver.
Doctors in Perth and South America told Mr Stitt and his wife Arely that the girl would die without urgent treatment.
But they refused until Tamar was too sick to walk, and she died of septic shock after the drugs were belatedly administered.
An inquest is being held to probe how Tamar died, and whether immediate chemotherapy could have saved her.
And on the witness stand, Mr Stitt told how he had been treated for a cut thumb, chest infections, and knee injuries using the red clay, which is wrapped in a towel and pressed on the affected area for hours.
Mr Stitt admitted the first time his wife suggested the treatment, when he cut his thumb, he was incredulous.
"I asked her if she was mad," Mr Stitt said.
But he told the inquest the cut healed, without infection.
And with his wife's family insisting they had been cured of all manner of illnesses - including cancers - by the clay, that was the treatment that was suggested by them for Tamar.
"I have to admit I was skeptical to begin," Mr Stitt said.
Mr Stitt said his mother-in-law, who now lives near Kenwick, still uses the mud sourced near her home to treat herself and her husband, and the same mud was used on him.
The inquest continues.