The Hawks are raiding properties belonging to the ex-husband of murdered Pretoria mother Chanelle Henning.
Hawks spokesperson, Macintosh Polela, confirmed the search and seizure operation, saying the warrants were being executed as part of a wider investigation.
Nico Henning is the ex-husband of 26-year-old Chanelle Henning, who was shot dead last November while dropping off her five-year-old son at a pre-primary school in Faerie Glen, Pretoria.
Police questioned Henning shortly after the murder but he was released without charge.
Two men involved in the murder are already serving 18-year jail sentences for their involvement in the killing.
A third accused, former Nigerian Olympic athlete Ambrose Monye, is still awaiting trial.
