A fourth Dutch gynaecologist has been identified as having used his own sperm in fertility treatment during the 1970s and 1980s.

The revelation comes after a third such fertility scandal, which emerged in public only last week, was described as “the tip of the iceberg”.

The latest rogue doctor has been named as Henk Nagel, who fathered at least one child between 1977 and 1985 at the Carolus Hospital fertility clinic in Den Bosch, now part of the Jeroen Bosch hospital group.

The chairman of the hospital board of management, Dr Piet-Hein Buiting, said Dr Nagel’s actions had been “incomprehensible and inadmissible”. He confirmed that an investigation was under way to try to establish whether Dr Nagel might also have fathered a number of other children.

The latest case came to light when a person born as a result of fertility treatment approached the hospital and said he was trying to find his biological father.

DNA tests carried out as a result of that search found “matches with blood relatives of the former gynaecologist” Dr Nagel. The hospital approached Dr Nagel, by then retired, and further tests confirmed he was the person’s father.