Kostas Kenteris has said he did not know he was expected for a drugs test, in his seven-hour testimony to public prosecutors in Athens.
The Greek sprinter quit the Games on 18 August after failing to show up for a drugs test before the opening ceremony.
Hours after the missed test, Kenteris and Katerina Thanou claimed to have been involved in a motorbike accident.
His lawyer Mihalis Dimitrakopoulos said: "He met a lot of officials and no-one said he was called for a test."
Both Kenteris and Thanou have repeatedly said that they are clean.
Prosecutors are also investigating the nutritional supplement businesses of their coach Christos Tzekos.