German umpire Nico Helwerth was not appointed to officiate a match at Wimbledon on Monday following his controversy on Centre Court. The 40-year-old failed to intervene when the electronic line calling went down during Sonay Kartal's loss to Anastasia Pavlyuchenkova.

Kartal hit a forehand which bounced a foot beyond the baseline. Pavlyuchenkova stopped playing because it was so obvious that she won the point. However, a manual error led to the AI not being switched on for that game.

Umpire Helwerth had the authority to overrule the technology but he failed to do so. Pavlyuchenkova fumed that the point was "stolen" from her.

The incident came at a key moment in the match, with Pavlyuchenkova serving on advantage at 4-4 in the first set.

The point was controversially replayed and Kartal went on to break. However, the Brit failed to serve out the set and lost in a tiebreak. She then lost the second set 6-4.

The official line from Wimbledon is that Helwerth is on a scheduled day off.

During the incident, Pavlyuchenkova raged: "I don’t know if it’s in or it’s out. How do I know? How can you prove it? Because she is local, they can say whatever. You took the game away from me."

She added: "They stole a game from me. They stole it."

Wimbledon launched a langthy investigation after the match and issued an apology. Their statement read: "We have had the opportunity to undertake further investigation, including speaking to the players, Chair Umpire, Hawk-Eye operators and Review Official. It is now clear that the live ELC system, which was working optimally, was deactivated in error on part of the server’s side of the court for one game by those operating the system.

"In that time there were three calls not picked up by live ELC on the affected part of the court. Two of these were called by the Chair Umpire, who was not made aware that the system had been deactivated.

"Following the third, the Chair Umpire stopped the match and consulted with the Review Official. It was determined that the point should be replayed. The Chair Umpire followed the established process. We have apologised to the players involved.

"We continue to have full confidence in the accuracy of the ball tracking technology. The live ELC system relies on the Hawk-Eye operators, the Review Official and the technology to work in harmony. This did not happen. In this instance there was a human error and as a consequence we have fully reviewed our processes and made the appropriate changes."

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