The case is expected to come before the International Olympic Committee's disciplinary commission and executive board, who meet tomorrow but refused to confirm the positive finding.
After Blonska's silver medal, Britain's Kelly Sotherton, who finished fifth, called for a worldwide policy to prevent drug cheats from returning to compete in the Olympics.
In a relatively quiet Games for drugs offenses, only four positive tests during the Games have so far been recorded by the IOC.
Meanwhile, at the Bird's Nest stadium today, Britain's Michael Rimmer survived a real scare in the first round of the 800 metres heats.
The Liverpool athlete, 23, was struggling as he was passed by Poland's Pawel Czapiewski and South Africa's Mbulaeni Mulaudzi at the start of the home straight.
But Rimmer kept battling to move wide and muscle his way back into the contest and make tomorrow's semi-final in 1min 47.61sec.
