JOHANNESBURG - Oscar Pistorius' agent has canceled all future races the athlete was contracted to take part in and says his "key focus" is now defending himself against the murder charge.

Peet van Zyl says there is "no option" but to cancel Pistorius' track dates indefinitely "to allow Oscar to concentrate on the upcoming legal proceedings."

Pistorius was arrested and charged with the Valentine's Day murder of model girlfriend Reeva Steenkamp.

He is being held at a police station in Pretoria, where agent Van Zyl visited him Sunday before announcing the double-amputee Olympian's track career is now on hold.

Van Zyl says Pistorius' sponsorships, including with big-name brands Nike and Oakley, are safe for now. He says "all parties are supportive and their contractual commitments are maintained."

Worker remove a billboard (bottom) featuring South African "Blade Runner" Oscar Pistorius near a street in Johannesburg, Feb 14, 2013. [Photo/Agencies]