Madeleine was three years old when she went missing on May 3 2007 while on holiday in Portugal.

Her disappearance sparked one of the most high profile missing persons searches in history.

Her parents, Kate and Gerry McCann have vowed to never give up looking for their daughter.

Last month marked Maddie’s 18th birthday with her parents saying every May that passes is a “reminder of years passed, of years together lost, or stolen”.

In a post on the Find Madeleine Facebook page, they said that Covid-19 has made the past year even harder, but thanked the police for continuing their investigation.

“We hang on to the hope, however small, that we will see Madeleine again. As we have said repeatedly, we need to know what has happened to our lovely daughter, no matter what,” the couple said.

“We still receive so many positive words and good wishes despite the years that have gone by. It all helps and for that we are truly grateful – thank you.”

Hans Christian Wolters, who is leading the police probe in Germany, told The Mirror: “We hope we can solve the disappearance of Madeleine McCann, although this will take several months,

“We are pleased with the response to our appeal for witnesses. But ­unfortunately not all our questions have been answered.”

Asked when suspect Christian B will be quizzed, he said: “At the end of the ­investigation. When we have completed our investigations, we will inform the public about the result and then also about further details.”

Despite this news former Scotland Yard detective chief inspector Peter Kirkham said he believes the inquiry is “rapidly drying up”.

Christian B was revealed as the new prime suspect in June 2020.