Captain Johannes “Jan” Taillard (1904–1987) was one of South Africa’s most effective and least known undercover policemen. Fluent in German and trusted across social divides, he played a decisive role in dismantling the Nazi Party in South West Africa in 1939, stealing the complete membership index and enabling the arrest of 2 284 members. In 1941 he infiltrated anti government networks in the Brits district, gained the confidence of Abwehr agent Robey Leibbrandt, and led him into a police ambush — an operation that prevented a planned assassination of Prime Minister Jan Smuts. Taillard’s long police career included senior command posts in Queenstown, Umtata, Johannesburg, and Cape Town, where he managed political unrest, labour strikes, and major security operations. Despite his contributions, his pension was severely affected by a break in service during undercover work, and his later life was marked by hardship. He died in 1987 without honours or police representation at his funeral. His story remains one of the most remarkable — and overlooked — chapters in South African policing history.