New research has warned the spread of niqab (a face-covering similar to a Burka) shops in Germany after an investigation has revealed they serve as Salafist meeting places and indoctrination centres.

TV magazine Report Mainz discovered such shops display Islamic State-related symbols, sell full veils for girls as young as two years old, and pressure customers to cover up. These businesses are “not just fashion shops, but part of Salafist infrastructure”, director of the Global Islamic Centre at the University of Frankfurt Susanne Schröter disclosed.

She added that the shops are centres “in which information is passed on and which function as meeting places for Salafists of both sexes. We now have a very solid Salafist infrastructure in Germany. The scene is clearly extremist, unsettling, and demands action.”

The programme investigated a shop in Frankfurt opened by the daughter of a Salafist preacher. The store, which has been advertised by notorious Salafist preacher Pierre Vogel, displays a poster declaring “my right, my choice” and “my right choice”, and another which says “Dress to impress Allah”.

Here, journalists witnessed a saleswoman pressuring a customer to cover up, telling her to “be strong” for Allah. The majority of visitors in the hour journalists spent there were women wearing full veils and men with beards considered to be part of the Salafist “uniform”. These customers reportedly stayed in the store for a “surprisingly long time”.

The Report Mainz team also spoke to an anxious mother whose daughter cut all contact with her mother and friends after converting to Islam. She asserted that niqab shops played a crucial role in her daughter’s radicalisation as she “visited relevant stores and veiled piece by piece”.

The mother explained: “Girls who convert do not do it immediately to 100 per cent. With the [guidance] of Salafist girlfriends you prepare step by step, how to dress. That’s brainwashing… every day.”

At a shop in Wuppertal journalists found products bearing motifs relating to Islamic State. Emblazoned on one T-shirt was the word “Tawheed”, and a picture of an outstretched index finger.

Associated with Islamic State, the terror group uses this finger symbol to allude to the tawhid, the concept of the indivisible oneness of monotheism in Islam. The Salafist concept of tawhid rejects non-fundamentalist regimes as idolatrous and ISIS members use the finger symbol to reaffirm their dedication to their ideology.

Also for sale were jumpers on which a creed is printed in white letters on a black background.

For Freiburg Islamic Studies scholar Adbel Hakim Ourghi, these are clear signs: “We see a close link with ISIS symbolism, which I consider to be propaganda, and it is dangerous for society here”. German Salafist Sven Lau, in court on suspicion of supporting a terrorist group, has advertised the shop on his Facebook.

At a shop in Berlin, which sits opposite a mosque known to host Islamist preachers, journalists found full coverage burqas and veils for two-year-old girls on sale for €19.90. The Report Mainz team reported being ejected from each shop when staff noticed their camera.

Other products found to be sold at these stores included veiled puppets and Quran-learning materials for three-year-olds.

Mr Ourghi, who regards the veiling of children as particularly serious, described the spread of niqab shops in Germany as “shocking” and “totally new”.

He said: “These stores compete, I would say, with socialisation here in the West with us. Especially when it comes to the indoctrination of children. We need not always wait until something happens. Such stores are a threat to our society and need to be under surveillance.”