A top Hawks investigator who cracked rhino poaching cases was killed assassination-style in Mpumalanga.

Lt-Col Leroy Bruwer, 49, died in a hail of bullets in Mbombela on the R37 connecting Mbombela and Lydenburg yesterday morning while heading to work.

He was the lead investigator of two high-profile rhino poaching cases - of former policeman Joseph "Big Joe" Nyalunga and suspected rhino kingpin Petrus Mabuza.

National police commissioner Gen Khehla Sitole said in a statement: "Colonel Bruwer, who was attached to the Directorate for Priority Crime Investigation [the Hawks], was driving to work this morning at 6.30am when he was shot at on Lydenburg Road in Nelspruit with what appeared to be heavy calibre weapons by unknown gunmen. Colonel Bruwer died on the scene.