A further 11 girls and young women have made a formal complaint in what police say is the biggest sextortion case uncovered in the Netherlands so far.

The new cases bring the total number of complaints against 24-year-old Gianni de W, to 19, officials told a pro-forma court hearing on Tuesday.

The public prosecution department says De W, from Etten-Leur, blackmailed more than 100 girls who had sent him nude photos of themselves. They have traced the identities of 130, 93 of whom are under the age of 18.

Police say they need a further three to six months to complete their inquiries and are still trying to contact 35 victims. The youngest known victim was just 13.

Investigators found 150 files with different girls’ names on De W’s computer, some of which contained thousands of photos of the same girl. ‘He made their lives hell,’ the public prosecutor told judges this week.

The man, who used variants on the name Bryan in his contacts, got in touch with the girls via social media and offered them cash in return for nude photos. He then threatened to place the images online unless they sent him more pictures.