Although no disciplinary action will be taken, the ATP said it would reevaluate the determination “should new evidence come to light, or should any legal proceedings reveal violations of ATP rules”.
The 15-month investigation was conducted by the Illinois-based Lake Forest Group and included interviews of more than two-dozen people and reviews of text messages, audio files, and photos submitted by Sharypova and Zverev.
“This included materials voluntarily extracted from Zverev’s electronic devices via a third-party forensic expert,” the ATP said.
The investigation looked primarily into accusations of abuse at the ATP Masters 1000 event in Shanghai in 2019 but also included “purported misconduct in other locations, including Monaco, New York and Geneva, as referenced in public reporting”.
Ultimately, investigators “found insufficient evidence to substantiate published allegations of abuse,” the governing body said.
ATP CEO Massimo Calvelli said turning to specialist investigators was “new ground” for the tour.
“We ultimately believe the exhaustive process was necessary to reach an informed judgement,” he said in a prepared statement. “It has also shown the need for us to be more responsive on safeguarding matters. It is the reason we’ve taken steps in that direction, with a lot of important work still ahead.”
Zverev lost to Michael Mmoh in the second round of the Australian Open earlier in January.