Jailed Paralympic athlete Oscar Pistorius was taken to hospital on Thursday for overnight observation, an official said, as local media reported he was suffering chest pains.

Pistorius, 30, is serving a six-year jail term for murdering his girlfriend Reeva Steenkamp, a model and law graduate, in his Pretoria house in 2013.

The "Blade Runner", as he was known, has always maintained that he mistook Steenkamp for an intruder when he fired four high-calibre bullets through a locked toilet cubicle.

"This morning he went for a medical examination and he was scheduled to return back (to jail), but he will now be kept overnight for observation," Logan Maistry, spokesman for the department of correctional services, told AFP.

Maistry added that the department would not release details on Pistorius's medical condition.

The News24 website said Pistorius was taken from Atteridgeville prison in Pretoria to hospital in an ambulance after complaining of chest pains.

The year before he killed Steenkamp, Pistorius became the first double-amputee to race at Olympic level when he appeared at the London 2012 games.

While on parole he gave a television interview saying that an "instant fear" drove him to open fire.