President Idriss Deby announced an amnesty for "all Chadians who have for one reason or another left the country.
In early January Bongo survived a brief coup attempt by army rebels while in Morocco.
"I was elected president of the republic - I cannot fall back on being an MP, never!"
Maurice Kamto and more than 150 supporters are being held for "common law" offences
"The reasons why we took up arms against the authorities have not been addressed" - Spokesman
The UFDD rebel group said instead of the army they were met by the Toros-Boros, Sudanese rebels, "who opened fire."
Since their deportation, the 47 have been held in secret at a high-security facility at police headquarters in Yaounde.
Katumbi filed a passport application at the Congolese embassy in Brussels.
Lucha is a pro-democracy civil rights movement in DR Congo whose name means "Struggle for Change"
Last year, authorities outlawed the main opposition party, the Citizens for Innovation