“The laboratory that does the typing uncovered the fact that the stallion Alexis-Z could not be the son of Almé-Z. The bloodtyping of Alexis-Z received from Germany included only two markers, meaning new blood needed to be drawn. At that time it was concluded that, on the basis of three markers that are very typical for offspring of Almé-Z, Alexis-Z could not be his son. A second test confirmed this result (pub. 4/14/1994). At the date of this publication (5/11/1994) it not yet clear how this occurred. The Zangersheide stud, where Alexis-Z was born, has tried to prove on the basis of the available documentation that the fault was not made there. It has been investigated - and is still being investigated - if it is possible to determine the sire. Parentage can be determined through blood typing with 98% certainty. The stallion committee is of the opinion though that the blood typing will not give the final answer.“
Photo of young Onze Fons here https://www.kwpn.org/kwpn_database?horse=p-314136