The 19-year-old, who won two of Greece's six medals this month, a gold in the 25-metre pistol event and a bronze in the 10-metre air pistol, said she was not invited to the ceremony due to her recent criticisms over state support for athletes.
"The truth is I was never invited by anyone and any efforts trying to falsify this truth, in order to justify their unjustifiable 'mistake', is sad and undignified," said Korakaki in a statement on her Facebook account.
"The fact I'm on holiday is just a good excuse for those who decided I shouldn't be there ... because I believe they did not in fact forget but actually they chose this.
"It has made me terribly disappointed that nobody informed me or even asked me, as had been agreed, and this comes on top of dozens of similar incidents and behaviour I've been faced with," she added.
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"It's like 'Korakaki doesn't exist, didn't go to Rio and didn't achieve anything, she's just a ghost'." Korakaki is in France but said she was informed the ceremony would take place in early September and that she would be informed if any date changes were made.
The government was left embarrassed when the tribute event led by Greece President Prokopis Pavlopoulos went ahead without Korakaki.
Earlier, the Hellenic Olympic Committee (HOC) played down suggestions she was deliberately snubbed.
"It's not a case of the athlete not being invited," a HOC spokesman said. "The decision by the government to hold the event came late yesterday afternoon and many other athletes could not attend.
"Some athletes have in fact just returned from Rio today. The state is planning another event when the whole team can be present."
(Editing by Tony Jimenez)
