| Games |
Sport (Discipline) / Event |
NOC / Team |
Phase |
Unit |
Role |
As |
|
|
1936 Summer Olympics
|
Water Polo (Aquatics) |
 NED |
|
|
|
Jan de Vries |
|
|
Water Polo, Men
(Olympic)
|
|
Match #2 |
Germany — Austria |
Referee |
|
|
|
Water Polo, Men
(Olympic)
|
|
Match #4 |
Germany — Sweden |
Referee |
|
|
|
Water Polo, Men
(Olympic)
|
|
Match #2 |
Sweden — Great Britain |
Referee |
|
|
|
Water Polo, Men
(Olympic)
|
|
Match #6 |
Hungary — Great Britain |
Referee |
|
|
|
Water Polo, Men
(Olympic)
|
|
Match #4 |
Germany — Czechoslovakia |
Referee |
|
|
|
1948 Summer Olympics
|
Water Polo (Aquatics) |
NED |
|
|
|
Jan de Vries |
|
|
Water Polo, Men
(Olympic)
|
|
Match #3 |
France — Greece |
Referee |
|
|