|Other names||Reinaldo van Groede|
|Occupation||Lawyer, immigration officer|
|Employer||División de Informaciones|
|Known for||Politician, founder of the Algemeene-SS Vlaanderen|
|Flemish National Union|
Lagrou had first came to prominence as a member of the Flemish National Union. He published his own journal Roeland, which became increasingly anti-Semitic following Adolf Hitler's rise to power. Following the German occupation of Belgium in World War II Lagrou, along with Ward Hermans, was the founder of the Algemeene-SS Vlaanderen (from 1942 the Germaansche SS in Vlaanderen), the Flemish SS.
Lagrou saw action with the Waffen SS on the Eastern Front and some initial reports erroneously suggested that he had died in battle. However Lagrou had survived and he was captured by the Allies in France but managed to escape to Spain.
In May 1946 his was one of three names on a 'black list' sent by the government of Belgium to Spain where he was in hiding, along with Léon Degrelle and Pierre Daye. Soon after he was condemned to death in absentia by the war crimes tribunal in Antwerp.
With the possibility of extradition from Spain looming Lagrou arrived in Argentina in July 1947 and adopted the false name Reinaldo van Groede. Here he became a leading figure in the ratlines sponsored by Juan Perón to rescue Nazis from prosecution in Europe. Given wide powers within the Immigration service in Argentina, Lagrou drew up ambitious plans to move as many as 2 million people from Belgium, all either Nazi collaborators or their families. He was also a member of the Rodolfo Freude-led División de Informaciones and in this capacity initiated the cases for resettlement for a number of Nazis.
- Dan Mikhman, Belgium and the Holocaust: Jews, Belgians, Germans, Berghahn Books, 1998, p. 176
- David Littlejohn, The Patriotic Traitors, London: Heinemann, 1972, p. 155
- Mikhman, Belgium and the Holocaust, p. 172
- Uki Goñi, The Real ODESSA, London: Granta Books, 2003, p. 112
- Goñi, The Real ODESSA, p. 89
- Goñi, The Real ODESSA, p. 113
- Goñi, The Real ODESSA, p. 175