The reward was announced at police headquarters in Parramatta yesterday morning.

Homicide Squad Commander, Detective Superintendent Michael Willing, said Strike Force Carica II, under the leadership of Detective Sergeant Peter Smith, had conducted extensive inquiries into Jessica’s disappearance in recent years both in NSW and interstate.

“That includes the forensic examination of several vehicles similar to that described by Jessica’s friend, interviews with former workers at an Oberon timber mill where a man who might have met the girls the night Jessica disappeared worked, and excavations at a riverbank in O’Connell,” Det Supt Willing said.

“Unfortunately, those leads have not enabled us to find Jessica, but we are hopeful that the reward may prove to be an incentive for someone to come forward with new information.”

NSW Police Minister Stuart Ayres said Jessica’s family had gone almost two decades without knowing what had happened to her.

“We hope that someone out there has the answers that Jessica’s family so desperately want and need,” Mr Ayres said.

“Police have worked tirelessly on this investigation and spoken to hundreds of people, but there could be someone else out there with new information that could help this case move forward.

“I implore any person who has not yet spoken to police to come forward and tell them what they know.”

Detectives are also keen to hear from anyone who has knowledge of the vehicle used in the incident.

The white VK Holden Commodore sedan had an orange blanket covering the back shelf above the rear seat, as well as a number of holes in the front passenger foot-well.

The reward of $100,000 is available for information that leads to the arrest and conviction of the person or people responsible for Jessica’s disappearance and suspected murder.