A Dutch court on Friday ordered a man who judges said had fathered between 500 and 600 children around the world to stop donating sperm.

The 41-year-old Dutchman, identified by de Telegraaf newspaper as Jonathan Meijer, was forbidden to donate more semen to clinics, the court ruling said. He could be fined 100,000 euros ($110,000) per infraction.

The court also ordered Meijer to write to clinics abroad asking them to destroy any of his semen they have in stock, except doses reserved for parents who already had children by him.

The decision came after a civil case started by a foundation representing the interests of donor children and Dutch parents who had used Meijer as a donor.

They argued that Meijer’s continued donations violated the right to a private life of his donor children, whose ability to form romantic relationships are hampered by fears of accidental incest and inbreeding.

Meijer’s mass donations first came to light in 2017 and he was banned from donating to Dutch fertility clinics, where he had already fathered over 100 children.

However, he continued to donate abroad, including to the Danish sperm bank Cryos which operates internationally. Meijer also continued to offer himself as a donor on sites matching prospective parents with sperm donors, sometimes using a different name, according to the Algemeen Dagblad daily.