A 41-year-old Dutchman who fathered between 500 and 600 children around the world has been ordered by a court to stop donating sperm.

As per the national guidelines in the Netherlands, sperm donors are allowed to father a maximum of 25 children with 12 mothers, according to Sky News.

The prolific donor, identified only as Jonathan M under Dutch privacy rules, provided sperm to several Dutch fertility clinics, a facility in Denmark and people he met through advertisements and online forums, the Hague District Court said in a written judgement.

His lawyer said his client wanted to help people who would otherwise be unable to conceive.

But the judge who heard the civil case said the donor “deliberately lied about this in order to persuade the parents to take him as a donor”, according to a statement from the court.

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, Reuters reported.

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 is 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.