Dozens of children conceived with sperm from a fertility clinic run by the late doctor Jan Karbaat have won the right to have their DNA checked against his.

Karbaat, who died in April 2017, is thought to have fathered at least 47 children via his own clinic in Barendrecht. Until now, his DNA profile has been kept secret.

His widow has resisted efforts to give his possible children clarity and Karbaat himself always denied the allegations.

Judges ruled in 2017 that items collected from Karbaat, reportedly including a toothbrush, nose hair trimmer and support stockings, could be tested for dna but that the results must be sealed pending the outcome of further court cases.

The clinic was closed in 2009 for failing to meet storage standards and irregularities over paperwork.

Dutch law limits the number of people who can be conceived from one sperm donor to 25, and children have the right to find out their donor’s identity when they are 16.

Judges at the court in Rotterdam said on Tuesday that the children had waited in uncertainty long enough and did not have to wait for the outcome of any potential appeal before getting access to Karbaat’s DNA.