The Oscar Pistorius legal team loses again
On Friday, Masipa ruled that state lawyers could proceed with their challenge to the verdict she gave in October.
"In my view, to entertain this application would be tantamount to reviewing my own decision … Accordingly the order that I grant in this matter, is to strike off the application," she said in response to a plea by Pistorius's legal team, which had sought to block the state's appeal.
It was not immediately clear when the state's appeal over the original ruling would be heard.
Pistorius, who lost his lower legs as a baby, said he accidentally shot Steenkamp after mistaking her for an intruder at his home but prosecutors sought to prove during his trial that he had killed her after an argument.
Masipa's decision to rule out murder was criticised by legal experts as an erroneous interpretation of the law.