A man accused of speeding on the N1 near Midrand appeared in the Pretoria Magistrate's Court on Tuesday.

Gauteng traffic spokeswoman Busaphi Nxumalo said David Hack, 55, would be back in court on August 7.

His son, Adam Hack, 20, pleaded guilty to reckless and negligent driving on Monday and was fined R1500 for driving at 188km/h.

Both men were arrested on Sunday for speeding in their Porsche GT3s. David was driving at 234km/h, ahead of Adam.

They face charges of reckless and negligent driving, with an alternative charge of exceeding the general speed limit of 120km/h.

Nxumalo said Adam was a South African Olympic swimmer, but Swimming SA could not confirm this. The South African swimming team for the London Olympic Games is in camp in Monaco, hosted by Princess Charlene of Monaco, an ex-South African Olympic swimmer.