A sperm donor in the Netherlands is the center of a fertility scandal after an investigation showed that he had fathered 102 children by donating at 11 different clinics.

An investigation into the man, who has not been publicly named, was launched after single mothers warned the authorities of a donor who gave his sperm at several clinics.

Sperm donors are supposed to sign contracts agreeing not to donate at different clinics, though the rule is not often checked or enforced.

By law, a sperm donor in the Netherlands is only allowed to sire 25 children to limit the chance that conceived children would later end up in a relationship not knowing they are half-siblings.

Authorities found that the man in question was able to donate at 11 different clinics and father 102 children An investigation into the man, who has not been publicly named, was launched after single mothers warned the authorities of a donor who gave his sperm at several clinics

Authorities found that the man in question was able to donate at 11 different clinics and father 102 children.

The Dutch Ministry of Public Health warned that oversight is lacking in fertility clinics, according to an analysis of the Artificial Insemination Data Foundation, which oversees the data of sperm donors.

The donor of the 102 children was tracked down and told a Dutch daily that his motive 'was not to have as many children as possible'.

He said: 'I just like to do it and to make people happy. It makes me feel helpful. The gratitude of doctors and prospective parents is great.'

The man said: 'Clinics are already happy if they have a donor who passes the screening.' He said that his sperm was 'often immediately used'.

Another man was also caught having donated his sperm to multiple clinics, but he had fathered only two children.

The Dutch association of gynaecologists (NVOG) called sperm clinics to immediately stop using the sperm of the two men.

It pleaded for a central sperm and egg donor registration 'to prevent such situations from happening'.

By law, a sperm donor in the Netherlands is only allowed to sire 25 children to limit the chance that conceived children would later end up in a relationship not knowing they are half-siblings

Both men even offered their sperm outside of clinics on the internet and through personal contacts as well.

The health care inspectorate has launched an official investigation into the matter.

Earlier this year, another scandal broke out around the head of a fertility clinic, with a DNA test proving that he illegally used his own sperm to father at least 19 children with unsuspecting women.

Controversial sperm doctor Jan Karbaat, who operated the MC Blijdorp fertility clinic in the town of Barendrecht, near Rotterdam, used his own sperm in 19 cases instead of the prescribed sperm donor.

Controversial sperm doctor Jan Karbaat, who operated the MC Blijdorp fertility clinic in the town of Barendrecht, near Rotterdam, used his own sperm in 19 cases instead of the prescribed sperm donor

Some mothers even reported that before the insemination, Karbaat walked to a room next door saying he would get 'fresh semen'.

Karbaat died in April this year at the age of 89 and had denied for years that he had used his own sperm in the fertility clinic that he had operated since the 1980s.

The sperm doctor always declined to cooperate with a DNA test. One of his children however did give a DNA sample to the databank.

'Fiom' DNA Databank director Ellen Giepmans said: 'But only after Karbaat passed away could his DNA could be used for research.'

The amount of matches could increase if more parents who had undergone treatment at Karbaat's fertility clinic and their children come forward for a test.

Local media suspect the amount of children fathered by Karbaat could be as high as 60.

For years, there had been strong suspicions that Karbaat had used his own sperm instead of anonymous sperm donors.

Joey Hoofdman's parents visited the fertility clinic for IVF treatment using the sperm of Hoofdman's father, who has dark, curly hair.

Yet now-30-year-old Joey, who is blond, was shocked when he saw a picture of Jan Karbaat in his younger years and could see a very close resemblance between himself and the sperm doctor.

The detailed results of his DNA test, as well as other individuals, were not made public for privacy reasons.

Ties van der Meer, who represents the affected children and families in a foundation called Donor Child said the reactions of the mothers and children are 'extremely varied'.

Van der Meer said: 'They are shocked, but there is at the same time happiness that there is clarity. It is a bittersweet aftertaste.'

For years Karbaat's clinic had a reputation of being among the best fertility clinics in the Netherlands, with thousands of women finding their way to Barendrecht.

Van der Meer said: 'Once Karbaat was seen as the best doctor in this field. Now he is exposed as a scandal doctor.

'The can of worms is now opening at last. And we have no clue where this will end. All sperm clinics in the Netherlands once bought sperm from MC Blijdorp.'