While there are several clues as to the suspect’s whereabouts, a police spokesperson in Essen, North Rhine-Westphalia, said on Thursday, a “decisive lead” is still lacking.

Over the past few months, six young males between the ages of 16 and 23 are suspected to have been involved in at least six cases of alleged rape involving several adolescent girls, according to investigators.

But after the arrest of four of the men, and with investigations underway regarding the underage 16-year-old suspect, the public prosecutor’s office and police on Wednesday reported that the last remaining suspect – an 18-year-old male from Gelsenkirchen – had disappeared.

The suspects allegedly made initial contact with the young girls via social media and acquaintances. Then they lured them into remote areas and pressured them into performing sexual acts on them, according to a police report.

“These are particularly heinous and brutal acts,” said police spokesman in Essen, Lars Lindemann.

The acts took place in Essen and Gelsenkirchen, reported Focus Online, adding that the perpetrators afterward ridiculed their victims and bragged about their deeds online.

Investigators believe the young men are responsible for further sexual offences.

Only three victims – all 16-year-old girls – have filed complaints with investigators thus far. But police believe that there are more victims and have urged others to come forward.

The 18-year-old suspect. Photo: Polizei Essen