A former primary school teacher who is said to have sexually abused 70 children online, should be jailed for eight years, followed by compulsory psychiatric treatment, the public prosecution department told judges on Wednesday.

Bas G, from Vlijmen in Noord-Brabant, was arrested last August. He has been a teacher at a primary school in the town for more than 20 years.

The prosecutor claims G called himself Jeroentje and approached children online, asking them to perform sexual acts which he then filmed. He had contact with one girl for three years and they had met and had sex several times. He had first approached her when she was 12.

She told the police about the abuse when she heard G had been questioned by police about approaching and photographing children at a naturist campsite.

A search of his computer and telephone turned up thousands of photos and a Snapchat account involving 439 children from all over the country. There is enough evidence to prove he abused 70 of them online, some of whom were as young as seven, the department said.

At the hearing, the prosecutor dwelt at length on the seriousness of the case, citing the accused’s profession several times. “The defendant in particular should have realised the seriousness of his actions and to have known how vulnerable children are,” he said.