Bemba and five co-accused were found guilty on appeal in March of bribery, corruption and of coaching 14 defence witnesses in the main trial.
The commission rejected the candidacy of Bemba, a rival to DR Congo President Joseph Kabila.
Bemba filed his papers at the electoral commission offices in the capital Kinshasa, throwing down the gauntlet to Kabila, who has ruled for 17 years.
A few minutes after landing, Bemba, accompanied by his wife, went into a VIP suite at the airport.
'Bemba "could fall within the ambit of article 10 of the electoral law" finding those who have convictions for corruption "ineligible'
Bemba's declared return adds a new and potent factor of uncertainty into what is already a tense election in one of the most volatile countries in Africa....
The DRC is in the grip of a crisis over the future of President Joseph Kabila
Bemba, 55, had appealed his conviction, a one-year jail term and a 300,000 euro fine imposed last year by the International Criminal Court (ICC) for bribing...
"The type of sentence, whether heavy or light, will send a clear message about the gravity of the crime," said Mariana Pena, from the Open Society Justice...
"Today's judgement sends a clear message that the court is not willing to allow its proceedings to be hampered or destroyed."
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