JOHANNESBURG, May 22 (Xinhua) -- The trial for the murder case against the Paralympic athlete Oscar Pistorius would be postponed for further investigation, the National Prosecuting Authority (NPA) announced on Wednesday.

The NPA spokesperson Medupi Simasiku said the investigation into the case was still underway and the concrete trial date could not be fixed right now.

According to the original plan, the case should be in court in Pretoria on June 4, but so far the prosecutors only expect postponement for further investigation, said the spokesperson.

In the early morning on Feb. 14, 2013, Pistorius'girlfriend Reeva Steenkamp was shot to death at his Pretoria's house, according to reports. Pistorius was charged with murder on Feb. 15.

He was granted bail eight days later, but was supposed to appear before the court in Pretoria on June 4.

Medupi Simasiku said it would be ready for trial if the investigation has been completed.

At the 2011 World Championships in Athletics Pistorius became the first amputee to win an able-bodied world track medal, while at the 2012 Summer Olympics he became the first double-leg amputee to participate in the event as entering the men's 400 meter and 4x400 meter relay races.

In the 2012 Summer Paralympics he set two world records by winning gold medals in the men's 400 meter race and the 4x400 meter relay.