Madeleine McCann was just three years old when she disappeared from an apartment in Portugal six years ago while her family was on vacation; now, a new team of detectives is about to breathe life into a case that has gotten new clues.

Portugal police are assisting Scotland Yard in the case and say they have new questions after reviewing thousands of documents from the original investigation. Authorities believe there’s a good chance Madeleine is still alive.

“We have visited Portugal on 16 occasions,” said Detective Chief Inspector Andy Redwood. “The Portuguese have worked with us. We are working carefully and closely together now in order to progress this case.”

McCann’s parents, Kate and Gerry, say they left their daughter and her siblings alone in their rental apartment in Praia da Luz while they went to eat dinner at a nearby restaurant; when they returned, she was gone without a trace. However, among the new clues are 38 persons of interest who are in the process of being interviewed, including Antonio Castela, a 73-year-old cab driver who says he believes he picked up Madeleine with two men and a woman the night after she disappeared.

Kate and Gerry McCann were initially considered suspects in their daughter’s disappearance, but the British couple have since been cleared. Scotland Yard says they will continue to work with Portugal in their fight to bring Madeleine–who would have turned 10 this May–home.

“The Home Office remains committed to supporting the search for Madeleine McCann. We have agreed to provide the Metropolitan Police with the resources they need to investigate her disappearance,” a Scotland Yard spokesman said in a statement.