Pistorius' prison sentence increased to 13 years, 5 months

In this Sept. 8, 2012 file photo, South Africa's Oscar Pistorius wins gold in the men's 400-meter T44 final at the 2012 Paralympics in London - the biggest moment of Pistorius' career. [File Photo: AP Photo/Kirsty Wigglesworth]

A South African appeals court has more than doubled the former Paralympian Oscar Pistorius's prison sentence for killing his girlfriend.

The Supreme Court of Appeal has increased Pistorius' sentence from six years in prison to 13 years and five months.

The court has sided with an appeal by prosecutors, who challenged Pistorius' original sentence as too lenient.

Pistorius shot and killed his girlfriend Reeva Steenkamp in the pre-dawn hours of Valentine's Day in 2013.

He claims he had mistaken her for a burglar.

He was initially convicted of manslaughter but also had that conviction overturned and replaced with a murder conviction by the Supreme Court.

He has served just over a year of that original six-year jail sentence.