Vanderbijlpark police are investigating a case of reckless and negligent driving against "blade runner" Oscar Pistorius, it was reported on Tuesday.

Pistorius suffered serious face injuries in a boating accident on the Vaal River on Saturday. A passenger on the boat suffered minor injuries.

"The Barrage police are investigating the possibility that Pistorius did not hit a floating object like a tree trunk, but collided with a pier," Inspector Kinnie Steyn said.

He said police divers found the boat Pistorius was driving at the bottom of the river near a pier which had been ripped from its straining posts.

A caretaker of the river property, David Mokhashane, said he noticed on Sunday afternoon that the pier had been damaged.

"On Saturday the pier was still okay," he said.

Pistorius, who is recovering from facial surgery, is expected to remain in hospital until the end of the week.

Pistorius was born without his fibulas and had to have both legs amputated below the knee when he was 11-months-old.

He astounded the world with speeds he could reach as a sprinter with the help of carbon-fibre prosthetics, running close to the times of top able-bodied athletes.

But at the same time, the International Association of Athletics Federations raised concerns over a possible unfair advantage from the "blades". Pistorius has won gold medals at the 2008 Paralympics in the 100m, 200m and 400m sprints (class T44). He also holds the world record in all three events.

Sapa