The no-ball call that denied England's Ben Stokes a wicket in his first over of the opening Ashes Test on Thursday led to the revelation that the third umpire was unable to check the front foot on every delivery.
Stokes bowled David Warner with the fourth delivery of his first Test over in more than nine months but the Australian was reprieved when TV replays showed the bowler's front foot had landed in front of the line of the return crease.
TV pictures showed his previous three deliveries at Brisbane's Gabba ground would also have been no-balls but the all-rounder was unable to correct his run-up as they had not been called.
Under International Cricket Council (ICC) regulations, the third umpire in World Test Championship matches is supposed to check every delivery for a no-ball.
Broadcasters later reported that the equipment used by the third umpire to check the front foot had broken down and the officials had reverted to the protocols used before the technology existed.
Unless the equipment can be repaired or replaced, the on-field umpires will call a no-ball if they see it but the position of the front foot will only be checked by the third umpire after the fall of a wicket.
ICC officials were not immediately available to comment.
Stokes, who was late to join the England squad in Australia after taking a break to focus on his mental health, was also denied his first Ashes wicket when he over-stepped the mark in the Adelaide Test in 2013.
Australian wicketkeeper Brad Haddin was caught behind for 51 but went on to make 118 after his reprieve. Australia won the series 5-0.
