Alexander Zverev was cleared on Tuesday after a 15-month ATP investigation into alleged domestic abuse charges against a former girlfriend at the US Open and elsewhere four years ago.

The German who is just back in action after injuring an ankle last summer at the Roland Garros semi-final against Rafael Nadal won a round this month at the Australian Open as he made his return to competition.

The ATP probe, which began in October, 2021, investigated claims of domestic abuse made by Zverev’s former girlfriend, Olya Sharypova. Incidents were said to have happened at the Shanghai Masters in 2019 as well as at the US 2019 and tournament venues of Monaco and Geneva.

The ATP cleared Zverev in the case: “A major independent investigation into Alexander Zverev has found insufficient evidence to substantiate published allegations of abuse,” the sanctioning body said in a statement.

“As a result, no disciplinary action will be taken by ATP.”

The probe was carried out by an independent detective group, the US-based Lake Forest Group with what the ATP said were investigators with more than 60 years of combined experience in the surveillance/investigation field.

The ATP added: “LFG conducted extensive interviews with both Sharypova and Zverev, and 24 other individuals including family and friends, tennis players, and other parties involved with the ATP Tour.”

The deep dive was said to have included “submissions by both Sharypova and Zverev, including text messages, audio files, and photos” plus “materials voluntarily extracted from Zverev’s electronic devices via a third-party forensic expert.”