The family of Oscar Pistorius have issued a statement expressing their concerns over online support groups appearing to criticise the Paralympic champion's girlfriend Reeva Steenkamp, who was shot dead on Valentine's Day.

The South African athlete is awaiting a murder trial following the death of the 29-year-old model, who was killed by four gunshots fired through a bathroom door in Pistorius's home in Pretoria.

Following the court's decision to grant Pistorius bail, a fan group, thought to be led by British woman Laura Lambden, emerged in support of the double amputee.

Supporters on social network website Twitter reportedly go by the name of 'Pistorians' and have posted a number of shirtless pictures of the 26-year-old under the hashtag #OscarPorn.

Along with expressing their support to Pistorius, some have commented on Steenkamp, with one tweet reading: "If you want to label me a #Pistorian because I say 'why are there so many tributes to Reeva when many women have died since her' so be it!" according to The Telegraph.

A statement released by Pistorius's family said: "The disregard that is being shown by some, specifically those commenting via social media, for the profound pain that Reeva's family and friends are going through is very troubling.

"There is not a moment in the day that Oscar does not mourn for his girlfriend and Reeva's family, and all those who were close to her, are in his thoughts constantly."

Pistorius is due to return to court in June.