Portuguese detectives investigating the disappearance of Madeleine McCann have asked for the case's secrecy limit to be extended beyond the usual eight months, officials said.
Portuguese law provides for an eight-month period where documents remain classified after police identify a formal suspect, with the deadline in the McCann case due to expire next week.
Police can ask for an extension and - while a case remains classified - official suspects, police and lawyers can be prosecuted if they discuss it in public.
A spokeswoman for the attorney general's office confirmed investigators had asked for an extension but she declined to provide details, although the Portuguese media said a three-month extension had been sought because of the complexity of the case.
No date has been given for any decision by the attorney general on the request.
Madeleine vanished last May, a few days before her fourth birthday, from her bedroom during a family holiday in the Algarve region.
The first formal suspect in her disappearance was Robert Murat, a British man who lives near the hotel from which she vanished. He has denied involvement.
Weeks later, Madeleine's parents Kate and Gerry McCann were also named as suspects. They have denied involvement in their daughter's disappearance and have launched a worldwide campaign to find her.
Murat and the McCanns have complained that they are unable to give their versions of events because of the secrecy laws.
Portuguese detectives met last month with forensic scientists from Britain who have examined evidence in the case.
