Dr Robert Trossel, aged 55, said he only discovered that a batch of vials sent to him in Rotterdam in 2006 carried the warning when he took part in a BBC Newsnight programme.
Dr Trossel also came to the attention of the Irish Medicines Board in 2006 when he began flying here to use Dr John Dunphy’s practice at Carrigaline, Co Cork, to provide such stem cell therapy.
Hundreds of patients were being charged €18,599 for a three-hour session before the service was deemed illegal according to EU regulations on the handling and quality of stem cells.
Dr Trossel told the GMC hearing that a TV crew accompanied a patient to film his treatment and interviewed Dr Trossel as they followed the entire process, he said.
Under a contract the clinic held with Advanced Cell Therapeutics (ACT) to provide stem cell therapy, the firm provided it with cells.
But as part of Dr Trossel’s procedures to comply with soon-to-be introduced European guidelines covering the tracing and sourcing of cells, a batch delivered to his clinic in August 2006 included new stickers providing information about where they came from.
He told the GMC hearing that a BBC cameraman spotted the name All Cells on the sticker next to the barcode and batch numbers.
Dr Trossel said he searched California-based All Cells on the internet and found a disclaimer stating it only produced materials for laboratory use.
Having contacted All Cells, he said: “We couldn’t get the confirmation so we immediately stopped all treatments with ACT patients.”
Dr Trossel said he was told by ACT the consignment was sent in error.
Dutch-trained Dr Trossel is alleged to be unfit to practice by administering stem cell therapy in an “illegitimate, misleading and dishonest” way.
The allegations relate to his treatment of nine men and women, the majority of whom were suffering from MS.