England angry over umpire's volume control

The South Africa captain had made 15 when third umpire Harper chose not to overrule his on-field colleague Tony Hill's not-out decision for caught behind.

England coach Andy Flower subsequently confirmed he was told by match referee Roshan Mahanama that Harper had not turned the volume up on his host broadcasters' audio/video feed to detect a noise which might have indicated Smith had edged the ball.

England were convinced they heard an incriminating sound as Smith flailed an attempted cut shot at a delivery from Ryan Sidebottom which ended up in the gloves of Matt Prior.

But Smith survived the decision review system appeal and went on to make 105 out of 215 -2 – sharing a second-wicket stand of 165 with Hashim Amla (73no) – as South Africa took control on day two of a final Test they must win to snatch a drawn series.

Asked whether England intend to make an official complaint over the handling of the decision, Flower said: "Yes, we will."

He recounted England's querying of the decision-making process with Mahanama, and the contradictory answers they received.

"I have seen the referee twice," he confirmed. "I first asked for clarification on the process and he explained the match referee gets a different audio feed to (broadcasters) Sky and Supersport.

"We found out that wasn't correct and one audio feed is used for everyone and the second time he said that Daryl Harper had not switched up the volume on his mic, and that is why we have heard the nick but the third umpire hasn't."

Flower admitted the sequence of events would have been comical if the stakes had not been so high at such a telling stage of an epic series.

"If it wasn't such a serious match for us I would have found it amusing," he said.

"I think it's very disappointing.

"They said they did not deem it necessary to turn up the volume."

Harper has already been under the microscope for some of his previous decisions in this series, notably his on-field gaffe in last week's third Test in Cape Town.

There, third umpire Aleem Dar had to correct a caught-behind verdict against Ashwell Prince whose bat was shown by video replay to be nowhere near the ball.

Flower is not yet a full convert to the International Cricket Council's DRS and his latest experience is hardly likely to help him change his mind.

"There are a couple of things we find illogical," he said.

"No 1 is that we don't use it for no-balls and there have been a couple of incidents when Kevin Pietersen and Graeme Smith have been out to no-balls in this series.

"No 2 is that Dave Richardson (ICC cricket manager) and Roshan Mahanama, before the series, explained to us in the absence of a 'snickometer' or 'hotspot', they would use an increased volume on stump mic for catches behind – they would turn up the volume for referrals – and we find it very disappointing they deemed this unnecessary."

Flower has no doubt Smith should have been given out.

"I have seen it, and it is very clearly an edge," he said. "It was a very important time at the start of the day when we needed early wickets and he is a big wicket.

"He has played well this series. It could have been crucial – we don't know what would have happened if he had been out. Of course, mistakes happen – we all make them – but when there is little logical reason for it then that is frustrating."

Smith himself conceded even he heard a sound as the ball passed his bat, but insisted he simply did not feel as if he had hit it.

"There definitely was a noise," he said. "But I didn't feel I'd touched the ball, even talking to (non-striker) Ashwell (Prince) as the review was going on I didn't feel the ball hit the bat.

"That can happen. Maybe I did, maybe I didn't."

Smith is struggling to come up with any other explanation but made it clear he has been true to himself.

He added: "I thought it was my thumb on the bat handle – and I still don't feel like I hit it."

Smith has no interest in guessing what may or may not have happened in the third umpire's room. "It's not my job to talk about what the third umpire looked at and heard," he said.

"We all knew what technology was available going into the series – that was explained openly and honestly by Dave Richardson – so to be crying over spilt milk now isn't right."

Smith is hoping his second successive hundred against England finally sets up a winning position for his team, who have dominated two Tests out of three so far yet still find themselves 1-0 down.

Sidebottom finally saw off Smith, caught at slip from one that left him off the pitch, shortly before the sticky weather broke spectacularly.

Three hours and 20 minutes later came a resumption which contained 23 balls, seven more runs and no wickets, before bad light brought an early close.