The News of the World claims the boy's biological mother is a poor unmarried Vietnamese woman named Pham Thu Dung, who abandoned him two days after giving birth. Previous reports have claimed that Pax's birth family had not been located.

The tabloid reportedly made contact with Dung's parents, who also signed the adoption papers. "Our daughter is a heroin addict and she is a bag of trouble. Her life has been ruled by drugs since she was 16," said the child's 55-year-old grandfather Chien.

"She disappears for months on end. Then just when you think you will never see her again, she's back. But we only ever see her when she wants money." "When she finds out that a rich movie star has adopted her baby, she will go after Angelina Jolie for money and make trouble for her. She may even try to take the child back."

The boy's aunt Trang, 33, told the tabloid that Dung still "loves" her child. "My sister thinks about her baby a lot. She dotes on my younger daughter and both my girls call her Mother. If she could, she would try to get her son back."

"She didn’t know she was pregnant until quite late on, otherwise she would have had an abortion. She took heroin all through the pregnancy and when the baby was born he was very underweight, just over four pounds."

Mr. Chien also said that his daughter was pregnant with the boy after having an affair with a married man at her working place, a textile factory. One month after childbirth, Dung’s parents took Pax to Tam Binh Orphanage.  After that, no one in the family visited the child.