Scotland Yard is reportedly travelling to Portugal to make three arrests in relation to the disappearance of British toddler Madeleine McCann A look into the Crimewatch special on the disappearance of Madeleine McCann. Courtesy BBC1. Breakthrough ... the last photo taken of missing British girl Madeleine McCann at age 3. THE parents of missing British toddler Madeleine McCann are nervously waiting as Scotland Yard detectives fly to Portugal to arrest three suspects. The Mirror reports Kate and Gerry McCann were being kept "fully informed" of police progress after being told of a breakthrough in the six-year-old mystery. The potential breakthrough follows last year's "cold case" review of all evidence surrounding the disappearance of the little girl six years ago while on a holiday with family and friends at the Praia da Luz resort in May 2007. RELATED: Who is this man? New face added to Maddie mystery New investigations included a meticulous combing of mobile phone data from the region at the time of the kidnapping. British media reports suggest the new suspects were a burglary gang who made a large number of calls to each other in the hours after Madeleine's disappearance. Fully informed ... Gerry and Kate McCann, the parents of missing British girl Madeleine, outside a court in Lisbon. The only potential holdup in the development is that Portuguese police are yet to grant a request for British police to operate in their country. Scotland Yard has reportedly requested permission from Portuguese authorities to interview and potentially arrest the suspects. A letter from the Crown Prosecution Service was sent to Portuguese police earlier this month. A source said to be close to the couple told The Mirror: "Clearly the fact that the police are out there is significant. Kate and Gerry will now be on tenterhooks as they wait for any potential developments. The Met are being very proactive and this is good news in the search for Madeleine and her abductor.