The first alleged sighting was made by a Norwegian woman, who reported seeing Madeleine at a petrol station in the Moroccan city of Marrakech on May 9 - six days after her apparent abduction.
It has now emerged that Kate and Gerry McCann were also told of a British tourist who contacted police on his return home from Morocco to say he thought he had seen Madeleine.
This second, separate sighting - which was passed on to the Portuguese and Moroccan authorities but not disclosed to the media - was in the same part of the city and at a similar time as the woman's. The Norwegian claimed she saw Madeleine outside a petrol station, while the British witness, who has not been named but is said to be from Yorkshire, said he saw a young girl with a close resemblance to Madeleine outside the Ibis Hotel opposite.
The Briton was unaware of the other sighting, meaning police had two independent reports in the same place, a source close to the McCanns told reporters.
Family spokesman Clarence Mitchell said: "We have been aware of it for months. It was made known to us when it happened. All I can say is that any possible sightings, if credible, we hope would be examined thoroughly, whether it's in Portugal, Spain or anywhere else."