Oscar Pistorius has formally called off the races that were due in coming months in the face of charges of murdering his girlfriend on Valentine's Day, his manager said on Sunday.

The Olympic and Paralympic athlete was charged on Friday with the premeditated murder of 29-year-old Reeva Steenkamp, who was shot dead at his luxury Pretoria home.

He had been contracted to compete in races in Australia, Brazil, Britain and the United States between March and May.