Seventeen years after Madeleine McCann disappeared, more than $400,000 of new funding has been approved for the police investigation.
McCann went missing on May 3, 2007, during a family holiday in Portugal - in what's thought to be the most high-profile missing persons case in history.
British media have revealed Scotland Yard had approved the new funding and report the total sum spent on the case is now close to $NZD28 million.
Veteran American journalist Robbyn Swan told AM the money continues to flow because the investigation is still open.
"Every year, about this time, the Met authorises a new tranche of money for the investigation with the proviso that they have to be making progress - there has to be something to spend that money on.
"Now, there is currently an ongoing investigation in Germany. They're also following additional leads and providing support to that case.
"But the bottom line is a little girl went missing in 2007. We do not know what happened to her."
The prime suspect in the McCann case, known as Christian B, is currently on trial in Germany for unrelated alleged sex offences against adults and children.
Swan says it's interesting German prosecutors have not gone forward with prosecuting the McCann case at this stage.
"There must be a reason," she told AM.
"They won't want to prejudice the ongoing investigation about Madeleine's disappearance by having people speak to the details of that now."
"It does make you wonder what they do have."
Swan says she's not sure we will ever know what really happened to McCann.
"The current suspect is not talking at this stage. If the current suspect was involved, I'm not sure we are going to get the full details but perhaps, in the fullness of time, we will get enough to satisfy us of what happened."
She says there's a good reason the case remains in the public eye.
"As people who investigate child abductions and missing children always say, relationships change over time, so if you keep the child's name in the media there is a chance that someone who knew something all along but didn't want to speak at the time for whatever reason will feel now I can speak and will come forward.
Madeleine McCann would turn 21 this year.
Asked if she believed McCann was still alive, Swan said there was nothing she knew of that points to that possibility.
"I've not any evidence that she is alive any more than I have seen any conclusive evidence that she is dead."
