Five Mexico players suspended from the country's Gold Cup squad after testing positive for clenbuterol have now returned negative tests for the banned substance.
Goalkeeper Guillermo Ochoa, defenders Francisco Rodriguez and Edgar Duenas and midfielders Antonio Naelson 'Sinha' and Christian Bermudez had all initially tested positive at a pre-tournament training camp.
When the tests were known, they were immediately placed on suspension by their country.
But the Mexican Football Federation have now announced in a statement the results of tests on the quintet performed at the laboratory at the University of California, Los Angeles, on June 10 were negative.
The federation added the players had requested the 'B' samples of their original May 21 tests now be analysed.
Officials have previously claimed contaminated meat was to blame.