South Africa's six-time Paralympic champion was sentenced to five years in jail in 2014 for shooting dead his girlfriend Reeva Steenkamp the previous year.

He was released after serving less than a year of his sentence in October 2015 but prosecutors successfully upgraded his conviction to murder which led to a six-year punishment.

The 30-year-old is expected to be granted "compassionate leave" to attend a memorial for his maternal grandmother Joyce Bekker after her death aged 93 last week.

According to the Daily Mail, Pistorius is considered sufficiently "low-risk" to be permitted to leave by prison bosses.

He was granted similar position in October to attend a memorial service for his paternal grandmother, Gerti Pistorius.

Pistorius, who has always maintained that he mistook Miss Steenkamp for an intruder, last week spent a night out of his cell in hospital.

He underwent medical examinations after complaining of "severe" chest pains.

"Tests were conducted, but the disabled athlete was discharged and is now back at the correctional facility," Department of Correctional Services spokesperson Logan Maistry told the Daily Mail.

Pistorius is eligible for parole in two years' time.

Prosecutors are, however, still attempting to overturn his six-year sentence at the Supreme Court of Appeal, claiming it is "shockingly low".