South African Paralympic champion Oscar Pistorius has asked the courts to force prison authorities to consider him for parole having served half of his 13-year sentence for murdering his girlfriend Reeva Steenkamp in 2013.

The former Paralympic gold medallist is seeking an early release over a dispute about when his sentence started.

A series of challenges and rulings by the Supreme Court of Appeal (SCA) has led to confusion about when his sentence became effective.

Pistorius argues that he has already served enough time in prison to be eligible for parole, and therefore authorities should look at whether he can be released early.

In 2017, SCA said that Pistorius should serve 13 years and five months for the murder of Ms Steenkamp – overturning a previous, more lenient punishment of six years for murder.

Last year, the same court ruled that his current term should be backdated to October 2014, when he was initially sentenced for a lesser charge of culpable homicide.

Pistorius argues that this backdating means he became eligible for parole in February last year.

He wants Gauteng’s High Court to order the parole board to convene a hearing for him. If that request is granted, he wants the hearing to be within 30 days of the order saying so.

But Atteridgeville prison, where he is being held, says the court of appeal has given contradictory rulings.

The Department of Correctional Services also says it is seeking a court judgement to establish the date when his sentence effectively began.

Steenkamp’s murder on Valentine’s Day nine years ago shocked the country. In the televised trial, which gripped millions in South Africa and around the world, Pistorius pleaded that he had shot his girlfriend four times because he thought a burglar had entered his Pretoria home.

But a panel of appeal judges found that having armed himself with a deadly weapon, Pistorius should have foreseen that whoever was behind the toilet door might die, especially given his firearms training.