The owner of the vehicle used to transport the two RFI journalists who were shot dead on Saturday has been formally identified as Bayes Ag Bakabo, a Tuareg, according to Malian security sources.
The source, who is close to the enquiry, said an accomplice whose name has not yet been revealed, is of Mauritanian nationality.
According to the source, Bayes Ag Bakabo belongs to the same tribe as Ambéry Ag Rhissa, the Tuareg leader from the MNLA interviewed by Ghislaine Dupont with Claude Verlon, just before they were killed.
They were abducted in front of Ambéry Ag Rhissa's house and killed less than two hours later.
Meanwhile French Foreign Affairs Minister Laurent Fabius said on Thursday that it seemed "plausible" that Al-Qaeda's north African branch had killed RFI's Ghislaine Dupont and Claude Verlon in Kidal in Mali on Saturday.
"We're in the process of verifying it, but it seems plausible," Fabius told French television.
Al-Qaeda in the Islamic Maghreb (Aqim) said in a statement published online on Wednesday that it had carried out the kidnap and killings "to punish France for her new crusade" in Mali.
France launched a military operation in January against Al-Qaeda-linked groups including Aqim, occupying the north of the country.
The French-led operation forced the extremists from the cities they had seized in the chaotic aftermath of a military coup that overthrew Mali's government in March 2012.
On Saturday a French military patrol found Dupont and Verlon's bodies about 12 kilometres east of Kidal, just hours after they were snatched, lying by the locked pick-up truck in which they had been abducted.
In his comments on Thursday, the French Foreign Minister said speculation that they were killed because the vehicle in which they were being transported after kidnap had broken down, was credible.
"The hypothesis of a [vehicle] break-down is possible," he said. "What is certain is that this car stopped in the desert and that was the moment in which our compatriots were assassinated by a hail of bullets, four bullets for one and seven for the other."