South Africa's highest court has rejected a request for appeal by Oscar Pistorius.
The decision means the "end of the road" for the former athlete's legal bid.
He faces 13 years in prison for the murder of girlfriend Reeva Steenkamp.
He had asked South Africa's constitutional court to review both his jail term and murder conviction, but both requests were dismissed in a ruling.
Pistorius shot Ms Steenkamp dead on Valentine's Day 2013 after firing four times through the locked door of his bedroom toilet.
He later claimed he believed she had been an intruder, and his lawyers have challenged both his prosecution and sentences in years of wrangling in the courts.
It now appears the former star will serve his full term, with no further recourse to appeal available.
"This is the end of the road. There are no other legal options available," national prosecuting authority spokesperson Luvuyo Mfaku said.
Pistorius was initially sentenced to six years in prison for culpable homicide - equivalent to manslaughter - after a high-profile court case.
But the term was slammed as "shockingly low" by prosecutors, and was doubled to 13 years after being upgraded to murder on appeal last November.
In making the ruling, the supreme court of appeal commented it was "difficult on the evidence" to accept Pistorius was "genuinely remorseful".