"The stem cells we harvest are amniotic cells, which means no harm is caused to the animals," he said.
"The stem cells are preserved because they are full of rich nutrients that fight free-radical damage to the skin and make it more radiant."
Beckham is also said to be a devotee of a "nightingale poop" facial made from the excrement of a rare bird found only on the Japanese island of Kyushu, the Daily Mail reported.
She is also said to slather on night cream containing bee venom in an effort to plump up her epidermis.
Agri-Lab production manager Angela Payne said she did not know Dr Lancer - Agrilab exported to wholesale distributors.
"They are a lot further down the food chain than us," she said.
"The product leaves us in 10kg bags of powder or 1kg bottles of serum - they are probably using the serum."
She said a placenta face cream was available in New Zealand, manufactured by Parrs.
She said a face mask made from horse placenta membrane was very popular in Hong Kong.
All suppliers must ensure placentas come from drug-free healthy animals.
"We have contacts with agents collecting pig, horse, dear and sheep placenta from all over the country. Farmers put them in the freezer, our agents collect the buckets and we process them further here."
Mrs Beckham's spokeswoman declined to comment on the placenta treatment.
