The older brother of the Toulouse gunman who killed seven people said he was “proud” of Mohamed Merah’s actions.
Abdelkader Merah told police he was present when the Yahama scooter used in the killings was stolen.
But he insists he had no prior knowledge of his brother’s criminal plans
The 29-year-old and his girlfriend are being questioned by French intelligence officers in Paris.
Mohamed Merah’s mother was also quizzed but has since been released.
Her lawyer said on Saturday that she was “wracked with guilt and full of remorse” for what her 23-year-old son did.
Merah murdered three Jewish children, a Rabbi and three French soldiers in an eight-day killing spree that has shocked France.
He himself was shot dead on Thursday after he opened fire on police following a thirty-two hour siege of his apartment in the southwestern city.
Questions are being asked over how French intelligence failed to apprehend the Merah brothers, who were known to have links to radical Islamists.
It has forced national security straight to the top of the agenda ahead of next month’s presidential election.