It’s the mystery that has captivated the world since May 3, 2007: as her parents dined at a restaurant just 50 metres away from their holiday apartment in the coastal town of Praia da Luz, Portugal, three-year-old Madeleine McCann disappeared from her bed.
She was last seen by her dad Gerry, who returned to the apartment at approximately 9:05pm to check on Maddie and her two younger twin siblings as they slept.
When Maddie's mother, Kate, checked the apartment almost an hour later, Maddie was gone.
After 10 years and almost $20 million worth of investment into the investigation, and there is still no clear idea of who took Maddie, where she is and if she is still alive.
Now, an investigation by Channel Seven's Sunday Night has revealed that Scotland Yard is desperate to pursue one last line of enquiry they believe might help finally solve the case and find Maddie.
"There is an employee, somebody who worked within the Ocean Villa complex who has some information or some knowledge that may be of assistance," former Scotland Yard police officer Colin Sutton to Sunday Night reporter Rahni Sadler.
It is unknown whether the employee in question is male or female, or what their role was at the holiday resort, but detectives believe finding this 'mystery' witness could bring them closer than ever to finding Maddie.