German police investigating Madeleine McCann's disappearance now believe she was killed in Portugal.
Police initially believed McCann was moved to Germany before she was killed but prosecutor Hans Christian Wolters says officers now believe this isn't the case.
Wolters said it's likely German suspect Christian Brueckner killed her in Portugal.
He has previously said "concrete evidence" will prove Brueckner murdered McCannn, but hasn't provided any more details.
When asked where McCann was killed, Wolters said, "In Portugal. I am optimistic we will solve this case".
His comments come days after McCann's parents marked what would have been her 18th birthday.
"Happy 18th Birthday Madeleine," the family wrote on their Facebook page.
"We love you and we’re waiting for you and we’re never going to give you up."
In June last year police identified 43-year-old Brueckner, a convicted rapist and paedophile, as the prime suspect in her disappearance. In July last year, police dug up an allotment in Hanover where Brueckner used to stay searching for evidence.
Brueckner, who is currently in prison for raping a 72-year-old American, is also suspected of raping another woman in 2004 near the resort McCann disappeared from.
Madeleine disappeared from an apartment in a Portuguese resort while on holiday with her family in 2007. Her parents were dining in a nearby bar and when they returned found Madeleine missing.