The two-bedroomed apartment in Praia da Luz was put on the market more than two years ago by the owner, a retired Liverpool teacher, but has not been sold and remains empty.

Madeleine was nearly four when she vanished while her parents dined with friends
in a nearby restaurant.

On the market: The apartment in Portugal from which Madeleine McCann disappeared

Still missing: Madeleine McCann

The neighbour said: ‘The flat has never been used again since the little girl went missing.

‘The shutters have stayed down and it is more like a mausoleum than the happy holiday letting it once was.

‘I still remember the night she went missing and a young female Portuguese officer saying, “She must have just walked out – there has been no break-in and the doors were left unlocked”.’

Meanwhile a new private investigation into Madeleine’s disappearance has begun in Portugal.

It is being run by three British former police officers: Nigel Brown, who was named Investigator of the Year after securing the rescue of a kidnapped oil company executive, Dave Carter, who worked in Northern Ireland, and Ray Cooper, who investigated war crimes in Bosnia and gang murders in Trinidad and Tobago.