Oscar Pistorius is seeking to appeal his murder conviction for the killing of girlfriend Reeva Steenkamp.

The athlete's legal team has asked South Africa's Constitutional Court to allow it to appeal the double-amputee Olympian's conviction.

Lawyer Andrew Fawcett said papers have been filed with the court "asking them to grant us leave to appeal".

It is not clear how long the Constitutional Court will take to decide whether it will hear Pistorius' case.

In December, an appeals court threw out a lower court's lesser manslaughter conviction and found Pistorius guilty of murder.

Pistorius shot Steenkamp through the door of a toilet cubicle in his home early on Valentine's Day 2013.