A video of a French family of seven kidnapped last month which also purports to show the alleged leader of Nigerian Islamist extremist group Boko Haram was obtained by AFP on Thursday.
Audio clips from the video were already reported by AFP earlier this week, but the video had been unavailable.
The video shows the purported leader of Boko Haram, Abubakar Shekau, as well as the seven French hostages. Shekau and the hostages are not together in the same location.
The man in the video resembles past images of the person previously identified as Shekau and his voice is similar. He wears camouflage and a rifle rests against his shoulder.
He says in Arabic in the nearly 11-minute video that the kidnapping was carried out because of the arrest of Boko Haram members or their family members in Nigeria and Cameroon.
The screen is split during part of the time he speaks, with one half showing him and the other a photograph of the family.
"God sent us the French hostages ...," he says in what is called a message to the presidents of Nigeria, Cameroon and France.
"The proof that we are holding them is that our brothers and sisters were captured in Nigeria and Cameroon ... We seek no money but the release of our brothers."
The father of the French family, which includes four children, the couple and an uncle, later reads a statement from a piece of paper.
He is surrounded by his children, his wife and his brother, all seven standing in front of what appears to be a tarpaulin.
A source close to the family on Monday confirmed that the man speaking was indeed the father, Tanguy Moulin-Fournier.
The family were on holiday in the region around Cameroon's Waza National Park when they were kidnapped on February 19.
The father says in the video that they were kidnapped 25 days ago.
Cameroon has said the victims were taken over the border into restive northeastern Nigeria after their abduction, though their precise whereabouts are unknown.
Boko Haram is believed to include a number of factions with various interests and shifting demands.
The group has in the past called for the creation of an Islamic state in Nigeria, where corruption is deeply rooted and most of the population lives on less than $2 per day despite its oil reserves.
However, criminal gangs, splinter factions and imitators also carry out violence sometimes attributed to Boko Haram.
Violence linked to the group's insurgency in northern and central Nigeria, including killings by the security forces, has left some 3,000 people dead since 2009.
Nigeria is Africa's most populous nation and largest oil producer, roughly divided between a mainly Muslim north and predominately Christian south.