Bongo was flown to Morocco on Thursday from Saudi Arabia where he had been in hospital since October 24.
Bongo, 59, was rushed to hospital in Riyadh on October 24 after falling ill at an economic forum.
Speculation about Bongo's future has swollen since the 59-year-old president was taken to hospital in the Saudi capital Riyadh on October 24.
The 59-year-old leader was in the Saudi capital for a flagship economic forum when he fell ill, said spokesman Ike Ngouoni in a statement.
"The legal requirements for opening an investigation into the situation in the Gabonese Republic ("Gabon") have not been satisfied," the statement concluded....
Security forces surrounded the opposition headquarters overnight and stormed the building.
Voters will soon known whether incumbent Ali Bongo has won a new term or been ousted by challenger Jean Ping.
"I have been elected. I am waiting for the outgoing president to call to congratulate me."
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