London (CNN) -- British girl Madeleine McCann, who vanished during a 2007 family vacation in Portugal, may still be alive, UK authorities said Wednesday.
Madeleine was a few days shy of her fourth birthday when she disappeared from her family's holiday apartment in Praia da Luz as her parents dined in a nearby tapas restaurant with friends. Despite a huge police investigation, massive coverage in the Portuguese and British media, and a public riveted on social media, she remains missing.
London's Metropolitan Police on Wednesday released a new image of the girl created in collaboration with the family that shows how Madeleine might look at age 9. Her ninth birthday is May 12.
An investigative review formed in May last year has been going through details from the case.
"As a result of evidence uncovered during the review, they now believe there is a possibility Madeleine is still alive and are appealing for anyone who is able to provide direct information as to her whereabouts to contact the team," police said in a statement, without disclosing any details on the possibility of new leads.
Investigators are combing through about 100,000 pages of information for more details, authorities said.
"The intention is to identify from that material investigative opportunities which we will then present to the Portuguese authorities who retain primacy for the investigation," police said. "Officers have so far identified around 195 such opportunities within the historic material, and are also developing what they believe to be genuinely new material."
Detective Chief Inspector Andy Redwood, who is leading a team of more than 35 officers focused on the McCann case, said they "will continue to put Madeleine McCann at the heart of everything we do." Redwood has visited Portugal seven times since the disappearance and has regular contact with the girl's parents.
The investigation is split equally down two lines -- one assuming that Madeleine is dead, the other that she is alive, police said.
Since her disappearance, her parents have appealed for help and said there's a chance she may still be alive. Frequent reports of sightings of her in various parts of the world have sparked frenzies. Last year, a report of a girl bearing a resemblance to the child created a spike on social media.
A spokesman for the girl's parents said the latest report is no more credible than other tips that proved incorrect over the years.
Portuguese investigators closed the case in July 2008.