The South African prosecution authority confirmed on Tuesday it would file an appeal against the culpable homicide verdict and five-year jail sentence handed down to paralympian Oscar Pistorius last month.
"Today, we announce that the NPA will file the application for leave to appeal both the conviction and sentence," the National Prosecuting Authority said in a statement on Tuesday.
"The merits of the NPA’s argument in this regard are contained in the papers that were filed with the registrar of the North Gauteng High Court today."
The Olympic and Paralympic athlete, whose lower legs were amputated as a baby, killed Steenkamp on Valentine's Day last year by firing four 9mm rounds into the door of a toilet cubicle, in what he said was the mistaken belief an intruder was hiding behind it.
Judge Masipa's decision to rule out murder was criticised by legal professionals and the Women's League of the African National Congress (ANC) as an erroneous interpretation of the law.
"We further announce, as we have indicated before, the appeal on conviction is based on a question of law," NPA spokesman Nathi Ncube told PowerFM radio.
Image: Oscar Pistorius sits in the Pretoria High Court for sentencing in his murder trial on Monday
Photograph: Werner Beukes/SAPA/Gallo Images/Getty Images
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