"France condemns the odious acts that followed the ceremony involving members of the Central African armed forces ... These abuses call for exemplary punishment," declared foreign ministry spokesperson Romain Nadal on Thursday.
Members of the Central African Forces were caught on camera beating and stabbing a man believed to be a Muslim to death and dismembering his body in front of a crowd shortly after a military ceremony at which Samba-Panza spoke of her pride in seeing the country's armed forces contribute to the nation's security again.
The perpetrators claimed the man was a member of the Muslim rebel Séléka militias and had been spying on them.
UN envoy Babacar Gaye late said that the murder was "unacceptable" and "must be properly investigated and the culprits punished and made an example of".
Gaye defende African Union forces who were present but failed to prevent the killing.
"Just because they are authorised to act does not mean that they should immediately engage in an armed confrontation," he said. "Lethal force should be used with restraint."
French forces are likely to stay in the CAR for longer than their initial six-month mandate, Defence Minister Jean-Yves Le Drian told RTL radio on Thursday.
France received the UN's backing for a military intervention in Central Africa last year and the government initially insisted that it would be brief.
But Le Drian said it was likely they would stay longer, while insisted that a UN mission should be sent.
"Otherwise this country, which is subject to regular atrocities, is in danger of falling into chaos and it's very dangerous for a country in central Africa - near risk areas like the Sahel, the Horn of Africa and the Great Lakes - to collapse," he told RTL radio.
French MPs will vote on prolonging the mission on 26 February.