French investigators on Monday questioned the brother of Toulouse gunman Mohamed Merah over suspected complicity in the murders of seven people in March, France Info radio reported.

Abdelkader Merah, 29, has already admitted to being present when his younger brother stole the scooter he used in the killings of three Jewish schoolchildren, three soldiers and a rabbi. But he has denied charges of being complicit in the murders and of conspiring to carry out terrorist acts.

Police suspect the elder Merah, who was under surveillance for links to radical Islamist groups, of having indoctrinated his sibling.

Mohamed Merah, who claimed links to al-Qaeda, was shot dead by police in a gunbattle on March 22 after a 32-hour siege of his apartment in Toulouse. He was 24 at the time of his death.