Detective Hilton Botha shared his thoughts and opinions on the Oscar Pistorius case during an interview with Vanity Fair magazine. File photo: Reuters

London - The former lead investigator on the Oscar Pistorius murder case has said that he is convinced the Paralympic gold medallist is guilty, according to a report carried in Vanity Fair magazine.

Detective Hilton Botha was heavily criticised for his bungling of the investigation into the shooting of Pistorius’s girlfriend, Reeva Steenkamp, who was killed in Pistorius’s house on February 14.

Botha stepped down after it emerged he faced his own charges of attempted murder for a 2011 case in which he and two other officers fired on a vehicle in an attempt to make it stop.

Pistorius, 26, is charged with murder of Steenkamp, who was shot after she locked herself in his bathroom in the early hours of Valentine’s Day. Pistorius claims he mistook her for an intruder.

The prosecution says it was a premeditated murder, but Pistorius’s defence advocate has argued there is no evidence to suggest the athlete’s account of events is untrue.

Speaking to Vanity Fair, Botha, who knew Pistorius from a previous arrest on assault charges, said: “It was just them in the house, and according to the security registers she had been staying there for two to three days, so he had to be used to her by that time ...

“There was no forced entry. The only place there could have been entrance was the open bathroom window, and we did everything we could to see if anyone went through it, and it was impossible.

“So I thought it was an open-and-closed case. He shot her - that’s it,” Botha was quoted as saying. - IOL