As a child Veleslav went to a local grammar school in Pankrác at Bělá pod Bezdězem.
He established an anti-communist organization along with Jaromír Nechanský which collaborated with the Office of Strategic Services, particularly the American secretary Walter Birge who was posted to the Prague embassy.
The Wahl-Nechanský trial also led to the Czechoslovakian government notifying the Americans that their embassy was too large due to their espionage activities and ordered them to reduce it to a third of its size.
A memorial to Wahl and others executed and tortured from the 1950s was established at Ďáblice, Prague, and in 2000, he was posthumously awarded the Honorary Medal of T.G.
Wahl wrote a landmark work on the birds of Prague (Pražské ptactvo), published first in 1944 with a second edition in 1945.