New photo of what Madeleine McCann would look like at age 18 unveiled to mark missing girl's birthday

Facial recognition technology experts have been able to produce an image of what missing girl Madeleine McCann could look like as her family marks her 18th birthday.

Days before her 4th birthday, Maddie went missing from a holiday apartment in Praia da Luz, Portugal while her parents were dining in a restaurant nearby.

More than 14 years on, Kate and Gerry McCann still hold out hope of finding out what happened to her, dreaming of finding her alive.

Now, thanks to technological advances, Bradford University professor Hassan Ugail produced an image that gives an insight to what Maddie could look like now.

Using AI technology, his approach maps out key features such as the shape of the cheeks, mouth and forehead.

The system uses machine learning to teach the computer how different people age, while also taking in the resemblance of family members to produce a photo-quality image.

The information was then fed into a computer algorithm that synthesises new features for the face to produce photo-quality images.

It is considered the most up-to-date image of Maddie anyone has ever seen.

Photo / Professor Hassan Ugail

Ugail told the Daily Star: "We take a photo, it doesn't matter what age the person is really, any age. So in the case of Madeleine, it's when she was 3," he said.

"Then, first of all, we get a picture of mum and dad and put it into the system and that provides our template and we put the age in as 17.

"When we say 17, we can't guarantee that but it will be something like 15 to 17 in a two- to three-year range.

"That's one reason we wanted to do this, to see if there's any hope ... anybody who looks at this picture and will think 'I know someone who looks like this'.

"Or even better, if the police can run it through large databases and then identify potential-looking people and then it can help with their investigation."

Christian Brueckner, the main suspect. Photo / Supplied

'DRAMATIC NEW EVIDENCE' AGAINST GERMAN PAEDOPHILE - POLICE

The e-fit comes as police have been given "dramatic" new evidence strengthening the case against prime suspect Christian Brueckner.

The 44-year-old convicted rapist is currently in jail in Germany and is accused as the man responsible for Maddie's abduction.

"We have gathered new evidence that adds further to the case we are building against our main suspect," German prosecutor Hans Christian Wolters said of the breakthrough.

"I'm afraid I cannot tell you what it is but it strengthens our work," he told The Sun.

"We are still building the case and at some time in the future, we shall share the details with the suspect and his lawyer — but now is not the time.

"I cannot disclose the type of evidence we have been given. It is not forensic, I can tell you that, but it is new circumstantial evidence which all adds to the working theory that he is the man responsible."

German authorities have said they have "concrete evidence" Brueckner murdered Maddie.

"We have always insisted that the man we identified as the main suspect is the man we believe committed the crime and we are not looking for anyone else.

"I am optimistic that we will solve this case."

And he added: "We have found no evidence that suggests he is not guilty of this crime and we have found a lot of evidence that suggests he is guilty but I am forbidden to go into these details."

Police are hopeful they will be able to charge Brueckner by the end of the year.

This article was first published on the NZ Herald and is republished here with permission.