JOHANNESBURG — The former lead detective in South Africa’s investigation of the murder case against the Olympian “Blade Runner” Oscar Pistorius has resigned from the police force, authorities said yesterday.

Detective Hilton Botha quit after criticism of his bungling of the investigation into Pistorius’ shooting of his girlfriend, Reeva Steenkamp, on Feb. 14, and the revelation that he faced attempted-murder charges for a 2011 case.

Botha was removed from the case last month and replaced with a more senior officer, Lt. Gen Vinesh Moonoo.

Police would not divulge Botha’s reasons for quitting.