ICC to investigate umpire DRS in Johannesburg Test

Question

The ICC has announced it will undertake an independent investigation of the application of the umpire Decision Review System, specifically the procedural issues surrounding the use of the technology, as applied in the fourth Test between England and South Africa this January.
The announcement of the investigation follows the ECB’s lodging of an official complaint regarding the use of the system in the deciding match of the series. The controversy about the use of the DRS broke out when third umpire Daryl Harper failed to give Proteas captain Graeme Smith out caught behind early on the second day’s play - and it has been alleged the reason for Harper’s decision was that the third-umpire didn’t have the volume turned up when watching the replay on his screen.