Technology is "not the aid it is claimed to be" in reviewing on-field decisions, the former international umpire Daryl Harper has said.

Having been at the centre of a decision-making storm that hastened his departure from Test cricket, Harper highlighted the problem of broadcast camera frame-rates as a central issue to the use of technology and the success or failure of the DRS.

In the series between West Indies and India, which did not employ the DRS, Harper said television cameras shot at 25 frames per second, while during the World Cup on the subcontinent, they were ratcheted up to 50 frames per second.

In each case, Harper believed, there was a high probability that the camera would not capture the ball landing or making contact with bat, pads or gloves, calling into question the veracity of replays and ball-tracking technology.

"When a batsman plays a shot well away from his body, and you as an umpire see the ball strike a glove, go through to the keeper, and you hear the sound, you can draw no other conclusion than it has been gloved to the keeper and the batsman is out," Harper told ESPNcricinfo.

"That it can't be confirmed by a camera at 25 frames per second, that's technology's problem. If they were filming at 1800 frames per second, like those super slow-mos, you'd see the glove depressed with the contact from the ball."

Even at the improved rate of frames utilised during the World Cup, Harper argued the evidence could remain sketchy, particularly for ball-tracking. This issue, raised consistently by the Indian board, had seen a revised version of the DRS introduced at the ICC's annual conference in Hong Kong.

The mandatory terms and conditions for the DRS that were approved consisted of infra-red cameras and audio-tracking devices. The ball-tracking technology has been removed from the ICC's original compulsory list of DRS technologies. This means that countries may still choose to use it, but can also use the system without ball-tracking, as will be the case in the upcoming England v India Test series.

"At 50 frames per second there is a very slim chance of the ball ever being captured making contact with the pitch when it actually lands, because there is a minimum of 60cm (of the ball travelling) between frames," Harper said. "If the cameras cannot capture the ball touching the pitch, I'm not quite sure how they can claim the degree of accuracy they do claim.

"So the more advanced technology becomes - unfortunately it is more expensive - the more likely the technology will be of a positive assistance to the game. At the moment it is not the aid that I believe it is claimed to be."

Harper's scepticism bears resemblance to that of India's players and board, as best articulated by N Srinivasan, the BCCI secretary. Before the ICC annual conference decided on a revised version of the DRS that eliminated ball-tracking technology, Srinivasan said the hardware had to be beyond suspicion if it was to be used.

"Nothing much has changed since we first opposed it. We welcome technology when it is 100% error-free," Srinivasan told the Indian Express in June. "In this case it is not, so we would continue to oppose the implementation of the DRS.

"The Hawk-Eye is yet to convince us. This is a technology that deals with the projection, trajectory and angle of the ball. And from where the cameras are placed, it cannot give a foolproof solution. We raised these issues when the company had made a presentation in Chennai and no-one was completely certain about its accuracy."