The Uzbekistan-born player was provisionally suspended in March but successfully appealed against her ban on the grounds that the meldonium traces came from tablets she stopped taking "on or around 20 December 2015".
The ITF, on the advice from WADA, said Lepchenko's samples were consistent with her account.
"It was accepted by the ITF that Lepchenko bore no fault or negligence for the violation and that any period of ineligibility that may otherwise have been imposed is eliminated entirely...," the ITF said in a statement.
"The results that Lepchenko obtained at the 2016 Brisbane International event are automatically disqualified..., and the points and prize money that she won are forfeit."
"This presence violation will be disregarded for sanctioning purposes in the event that Lepchenko commits any further anti-doping rule violation."
Russian five-times grand slam champion and former world number one Maria Sharapova is the sport's highest-profile athlete to be banned after testing positive for meldonium, a drug designed for heart conditions that increases blood flow.
The Court of Arbitration for Sport (CAS) is set to rule on Sharapova's appeal against a two-year ban in the first week of next month.
(Reporting by Nivedita Shankar in Bengaluru; Editing by John O'Brien)
