The brother of a French gunmen who killed seven people before being shot dead has said he is proud of what his brother did, according to a police source.

Mohamed Merah, 23, was shot dead on Thursday after a 30-hour siege of his apartment in Toulouse, south-west France. New video has emerged of the apartment where he was besieged before he opened fire on police as they searched for him. The gunman then jumped out of a window and was shot by a marksman.

His brother Abdelkader Merah was transferred to the Paris headquarters of the internal intelligence agency for questioning on Saturday. His unnamed girlfriend is also in custody while Zoulika Aziri, the mother of the two men, was released on Saturday.

During negotiations with police Mohamed admitted killing three children and a man at a Jewish school and killing three soldiers in two separate incidents. He also said he planned to shoot more soldiers and policemen.

Police found explosives in the car of Abdelkader, who is also believed to have had links with French jihadist groups. A police source said on Saturday that at a closed hearing in Toulouse he had declared himself "proud" of his brother's killings and had admitted helping Mohamed steal the scooter used in all seven murders. He denied any knowledge of his brother's plans to kill, the source added.

The president, Nicolas Sarkozy, summoned ministers and police chiefs to a meeting on Saturday to discuss the consequences of the massacre, which has raised troubling national security questions four weeks before a presidential election.

The shootings shifted the focus of political debate away from France's economic woes and played to the strengths of Sarkozy as he fights for re-election in a two-round vote in April and May.

Polls show that about two-thirds of voters approved of his handling of the Toulouse crisis, which reduced his challengers, chief among them the Socialist candidate, François Hollande, to the role of bystander.

Sarkozy's intelligence adviser, Ange Mancini, sought to head off increasing media debate about whether Mohamed could have been stopped before he started killing, saying the intelligence and police services had done an "exemplary" job and that it was always easy to ask after the fact if there were flaws.

"Obviously the aim now will be to dig deeper, not just to know more about the case in question but to see whether there are other lessons, to try to identify whether anyone else might be heading down the same road," Mancini told the news channel BFM TV.

Meanwhile, the pregnant girlfriend of a French soldier killed by Mohamed has been granted permission to wed her partner posthumously, a family lawyer said on Saturday.

The paratrooper Abel Chennouf was shot dead this month at a cash machine in Montauban, southern France.

The lawyer, Gilbert Collard, said Chennouf's pregnant girlfriend, 21-year-old Caroline Monet, is applying for permission to get married to her late partner at an official ceremony in a few weeks.

Such ceremonies are unusual but not unheard of in France, where the law allows posthumous marriages in cases where a fiance dies before the wedding. The law states that such weddings can only be approved by the French president "in grave circumstances".

"I've already had it done twice, for policemen's girlfriends," Collard said. "It's a really moving ceremony, with an empty chair representing the dead spouse."

Collard said the official request was being sent out on Saturday but he'd already received approval from the French president's office.

"There won't be any problems," Collard said, adding that he hoped the ceremony would "let the child have a father".