Sinner was ruled to bear no fault or negligence for the positive tests.

The ITIA described the levels found in Sinner's sample as "low". His lawyers said it amounted to "less than a billionth of a gram".

The full decision, published by the ITIA,, external states that Naldi cut the finger of his left hand on a scalpel in his treatment bag on 3 March.

Naldi bandaged the cut and unwrapped it two days later. Umberto Ferrara, Sinner's fitness coach, recommended the physio use a medical spray Ferrara had bought in an Italian pharmacy in February on the cut.

The physio said he did not check the contents of the spray, which he used every morning from 5-13 March, with Indian Wells taking place from 6-17 March.

Between those dates, Naldi gave Sinner full-body massages and applied bandages to his feet. He did not wear gloves while carrying out the treatments.

Sinner stated that he suffers from a skin condition on his feet and back that leads to scratching and can cause small cuts and lesions in the affected areas.

On the morning of 10 March, Naldi treated Sinner's feet and ankle. He said he would have applied the spray twice that morning, and that he "cannot remember" washing his hands between spraying his finger and treating Sinner's feet.

Sinner and his team co-operated fully with the investigation.

The ITIA accepted Sinner had no knowledge of either the spray or that it contained a prohibited substance, and did not know Naldi had used it on his cut finger.

Three independent experts also concluded Sinner's explanation was plausible, with one stating the amount administered "would not have had... any relevant doping, or performance enhancing, effect on the player".

The ITIA stated that the violation was not intentional before referring the case to an independent tribunal to determine "what, if any, fault the player bore and therefore the appropriate outcome".

The independent tribunal subsequently determined a finding of no fault or negligence, meaning the 23-year-old would not be suspended.

However, he will lose his 400 ranking points and $325,000 prize money from Indian Wells.

The ruling is also subject to any appeal by Wada.