Scotland Yard has confirmed detectives investigating the case of Madeleine McCann are pursuing "critical" leads as the 10th anniversary of her disappearance looms.
The little girl vanished at the age of three in Portugal on May 3, 2007. The child had been on holiday with her family at a holiday apartment in Praia da Luz.
Since 2011, investigators have examined more than 40,000 documents and examined 600 individuals. Kate and Gerry McCann have always held out hope their daughter - who would be around 13 years old now - will be found.
Mark Rowley, an assistant commissioner for the Metropolitan Police, said there were "significant investigative avenues" which the UK and Portuguese teams deemed to be of "great interest."
He said: "We have a significant line of inquiry worth pursuing, and it could provide an answer.
"Us and the Portuguese are doing critical work and don't want to spoil it by putting titbits of information out publicly."