Sinner provided an in-competition sample at the Indian Wells Masters on March 10, 2024 which contained the presence of a metabolite of clostebol at low levels, according to the ITIA.
A further sample, conducted eight days later out of competition, also tested positive for low levels of the same metabolite.
"ITIA today confirms that an independent tribunal convened by Sport Resolutions has ruled that Italian tennis player Jannik Sinner bears No Fault or Negligence for two Anti-Doping Rule Violations under the Tennis Anti-Doping Programme (TADP)," said the agency in a statement on Tuesday.
"The player explained that the substance had entered their system as a result of contamination from a support team member, who had been applying an over-the-counter spray (available in Italy) containing clostebol to their own skin to treat a small wound."
The ITIA added that the support team member in question had applied the spray between March 5-13 during which time they also provided daily massages and sports therapy to Sinner, which resulted in the contamination.
While the 23-year-old Italian has been cleared of any wrongdoing, he will be stripped of his results, prize money and ranking points from Indian Wells, in accordance with the anti-doping rules in force.
"I will now put this challenging and deeply unfortunate period behind me," said Sinner in a statement published on X.
"I will continue to do everything I can to ensure I continue to comply with the ITIA's anti-doping programme and I have a team around me that are meticulous in their own compliance."
