The ATP has announced that it will investigate allegations of domestic abuse against Alexander Zverev made by the player's ex-girlfriend.
The world number four is alleged to have physically and emotionally abused Olga Sharypova during their relationship, including an incident of violence at the Shanghai Masters in 2019.
Zverev has vehemently denied the allegations made by Sharypova, and the 24-year-old is said to have welcomed the investigation as he seeks to clear his name.
Following the announcement of the ATP's independent investigation, CEO Massimo Calvelli said: "The allegations raised against Alexander Zverev are serious, and we have a responsibility to address them. We hope our investigation will allow us to establish the facts and determine appropriate follow-up action.
"We understand Zverev welcomes our investigation and acknowledge that he has denied all allegations. We will also be monitoring any further legal developments following the preliminary injunction obtained by Zverev in the German courts."
Zverev - who lost to Novak Djokovic in the semi-finals of the US Open - is scheduled to take part in the 2021 Indian Wells Masters this month amid the investigation.