Amsterdam: The head of a Dutch fertility clinic is accused of using his own sperm and not that of selected donors to father dozens of children. Twenty three parents and children of those born through IVF treatment at Bijdorp medical centre, in Rotterdam, have gone to court to ask for DNA tests on Jan Karbaat, who died aged 89 last month.

Karbaat, who ran one of the country’s largest sperm banks in the Eighties and Nineties, billed himself as “a pioneer in the field of fertilisation”.

But reports began to emerge last year that suggested he may have been fathering the children he helped to conceive in a plot twist that echoes the popular TV crime drama Taggart.

Women who used the clinic report being told by Karbaat that he was fetching “fresh seed” from a room next to the insemination area. They say there are strong similarities between Karbaat and their children — including genetic features such as eye colour — that don’t match with their official donor’s characteristics. Karbaat reportedly admitted to having fathered about 60 children at the clinic, which closed in 2009 amid reports of irregularities, and requested in his will that no DNA tests be carried out on him post mortem.

“They say it feels like they were raped by Karbaat,” Tim Bueters, the lawyer for the families, told newspaper Algemeen Dagblad. He asked the court for permission for DNA tests on Karbaat, saying: “It’s a fundamental right to know where you came from. It’s a question of identity [and] helps someone to form their personality.”

But Lisette de Haan, the lawyer for Karbaat’s family, asked the court to respect the right to privacy and argued: “There is not the slightest evidence that Mr Karbaat was the donor.” Officials have already seized personal objects such as a toothbrush from his home, but the court could order a test on one of Karbaat’s legitimate children or call for the body to be exhumed.