Scooter terrorist Mohamed Merah 'was not a lone wolf'

Secret files reveal killer's sister had been watched by the French security services since 2008

The older sister of the Toulouse scooter killer, Mohamed Merah, had been under surveillance as a possible Islamist activist since 2008, it emerged yesterday. Souad Merah, 34, provided money, mobile phones and internet addresses to her brother in the months before his murderous attacks in the Toulouse area in March, the French radio station RTL reported.

Security files, made available to prosecutors last month, also reveal that Ms Merah had been under surveillance long before the killer was, RTL said. She was identified by French internal security services as a possible threat in 2008 – at the same time as another brother, Abdelkader, who has been in custody for six months.

Families of Merah's seven victims called yesterday for Souad Merah to be arrested and questioned. Although she was briefly interviewed after the murders, the inquiry has concentrated on the possible role of Abdelkader, Merah's older brother, in inspiring and assisting the killings.

Mohamed Merah, 23, died when police stormed his flat in Toulouse on 22 March after a 32-hour siege. In previous days, he had murdered three off-duty French paratroopers and three children and a teacher outside a Jewish school.

Merah, who filmed his murders, claimed to be working on behalf of al-Qa'ida. Security services believe he was a "lone wolf", inspired by extremist Islamist teaching but acting independently or with the help of his brother. According to the files of the French internal security service, the DCRI, seen by RTL, his sister may have played, at the very least, a role in his conversion to radical Islam.

Souad Merah was under surveillance from 2008 as a follower of an extremist Salafist Islamic movement in Toulouse. She also visited Koranic schools in Cairo. She appears in French security service files in 2008 as a "follower of radical Islam" and in June 2011 she is listed as being "known for her links" to radical Salafists. In the months before the Toulouse killings, she provided Mohamed Merah with cash, mobile phones and the use of her internet address on several occasions, according to the files seen by RTL.

The revelations will reinforce speculation that Mohamed Merah may have been less of a lone operator than he seemed – or than French security services have claimed. They will renew questions about the failure of the security services to monitor Merah and his siblings more closely.

Abdelkader Merah, 29, has been arrested and placed under formal investigation for complicity in murder, theft and association with criminals.

Lawyers for the families of Merah's victims asked yesterday why Souad Merah had scarcely been questioned after the killings. They said that the notes revealed by RTL "opened possible new avenues of investigation".