(CNN) -- British police have identified a number of "people of interest" in the disappearance of British girl Madeleine McCann during a 2007 family vacation in Portugal, London's Metropolitan Police said Friday. A review was launched in 2011 in an attempt to find out what happened to the British toddler who vanished from the family's holiday apartment in Praia da Luz on the Algarve coast, police told CNN. Police have been working closely with Portuguese authorities on the case. "The purpose of the review was to look at the case with fresh eyes and there is always real benefit in doing so. The review has further identified both investigative and forensic opportunities to support the Portuguese," Detective Chief Superintendent Hamish Campbell said. The girl was a few days shy of her fourth birthday when she disappeared.
Police identify a number of "people of interest" in the disappearance of Madeleine McCann . The British girl vanished during a 2007 family vacation on the Algarve coast of Portugal . UK police set up a review in 2011 in an attempt to find out what happened to the toddler .