The couple was taken into custody by border police upon their return to France, one day after the Air France Boeing 777 from Mauritius to Paris was diverted to Kenya.
The man, 58, is a retired policeman, a legal source said, with no further details about the couple or their nationalities.
The wife was also being questioned as a witness.
The alert came when a passenger found a suspicious item inside a toilet cubicle on board the Boeing.
The 473 passengers and crew were shortly evacuated after an emergency landing in Mombasa before police bomb experts examined the device which “appeared to be a kitchen timer”.
“The bomb scare appeared to be the result of a bad joke,” Air France chief executive Frédéric Gagey said.
However, the airline filed a legal action against unknown persons for endangering the life of others.
France is on high alert after the Paris attacks in November and has put in place extra security precautions.
“There have been three bomb scares on air France planes in the Unites States in the past 15 days,” added Gagey.
Source: rfi afrique