Madonna has angered the father of her adopted son David Banda by raising him in the Kabbalah faith.
The '4 Minutes' singer - whose official adoption of the two-year-old Malawian tot is soon to be finalised - and husband Guy Ritchie have been taking David to weekly meetings at the London headquarters of the Jewish sect.
A source close to Madonna - who has two other children, Lourdes, 11, and seven-year-old Rocco - told Britain's Mail on Sunday newspaper: "Madonna and Guy have been taking David to Kabbalah and he is very much a part of their Friday night ritual.
"David goes with Guy and the children, Lourdes and Rocco, for prayers and teachings. Madonna turns up later for the meal."
However, David's impoverished father Yohane Banda, who gave him up for adoption after his wife died, is a devout Christian and is worried about his son not being brought up in the same faith.
He said: "I expect my children to belong to the same church as me. To follow in my footsteps."
Of her religion, Madonna has previously said: "I believe in Jesus and I study the Kabbalah, so I don't see why he (David) can't too."
Yohane has also claimed Madonna has broken her promise to allow him regular access to his son.
He is quoted by Britain's Sunday Times newspaper as saying: "I was promised by Madonna that I would be able to see my son. The government people that were coming to see me also assured me that they would facilitate meetings with my son. I miss him so much, because he is my only son, the only gift of life from God - all the others have died."