(CNN) -- Parents of missing British toddler Madeleine McCann have learned for the first time of a possible sighting of the child just after her disappearance, and don't know whether Portuguese police pursued it, a family spokesman told CNN Wednesday.
Madeleine McCann went missing in May 2007 after being left at a holiday apartment in the Algarve region.
The possible sighting of Madeleine in May 2007 stemmed from a report by a Dutch shopkeeper, who told authorities she encountered a little girl in Amsterdam, the Netherlands.
She said the child identified herself as Maddie and said she was taken from her mother while on holiday.
"I start to ask where her mommy was," Anna Stam said. "She couldn't tell me that. I wanted to give her a balloon, but she didn't want that. She only wants her mommy, she said. And she said that these people took her from her mommy."
Madeleine was 3 when she disappeared May 3, 2007, while she was on holiday with her family at the Portuguese resort of Praia da Luz. Her disappearance prompted headlines worldwide.
Portuguese police last month closed their investigation into the girl's disappearance. Watch what the case file has so far revealed »
At one point, authorities had named the girl's parents, Kate and Gerry McCann, as "arguidos," or suspects, along with a British man living in Portugal, Robert Murat. But a spokesman for the Portuguese public prosecutor's office said authorities found no evidence of involvement by any of the three and were no longer considering them "arguidos."
After closing the case, police turned their case file -- containing up to 30,000 pages -- over to attorneys and private investigators working for the McCanns.
The couple only found out about the Amsterdam sighting in the past few days, their spokesman, Clarence Mitchell, told CNN, calling it "one of the scandals of this whole case." Watch how the McCanns hope the police file can still crack the case »
"Kate and Gerry did not know what exactly, was being done in the search for their daughter by the very police force that had that responsibility, and more importantly they had no idea what wasn't being done," Mitchell said.
Dutch police investigated Stam's report of a possible sighting, and turned it over to Portuguese police, who did not return calls from CNN on Wednesday.
There are some problems with the reported sighting. Stam claims the girl she saw had dark hair, while Madeleine's hair is light. Also, her parents insist she would not have referred to herself as Maddie.
Still, Mitchell said they would appreciate knowing how much attention Portuguese authorities paid to it, whether it was ruled out and if so, why.
"What we hope now is that the police will still at least have a spirit of cooperation with the private investigators who are now working internationally to find Madeleine," Mitchell said.
However, he noted "one of the greatest frustrations" for the McCanns has been the lack of communication with Portuguese authorities.
"It might shock you to hear that the officer in charge of the case has never actually spoken (to) or been in any formal contact with either Kate or Gerry -- the man who was responsible for looking for their daughter," Mitchell said.
Kate McCann wrote to the officer last year pleading for information, he said. Authorities did not reply, but the letter was added to the case file.
Also contained in the case file: the McCanns were declared arguidos based on DNA evidence that police knew was actually inconclusive; And sketches of men seen acting suspiciously in the area around the time of Madeleine's disappearance were made, but never released publicly or shown to the McCanns.
The McCanns have said Madeleine was abducted from her bed while they dined in a resort restaurant nearby. They initially faced criticism for leaving her alone, and police released sketches of a scruffy, mustachioed man whom witnesses claimed to have seen carrying a girl matching her description.
Mitchell said he and the McCanns do not believe the Portuguese police will reopen the case. Last month, authorities said it would only be reopened if new evidence surfaces.
Attorneys and private investigators are continuing to sift through the police case file, Mitchell said, and hold out hope that it contains "the key ... that unlocks the search for Madeleine."
The McCanns have said they believe the girl could still be alive.
"The chances of Madeleine being found are at least as good, if not better, than in those first few days," Kate McCann told CNN in May. "We know she's been abducted by a man. Other than that, we just don't know anything. There's a whole range of scenarios in which she could still be alive."
The couple has said they are trying to lead an ordinary life amid the campaign to find their daughter. Their now-3-year-old twins' routine of swimming lessons and nursery classes has provided a welcome distraction, they say, but a completely normal life is impossible while Madeleine remains missing.
"We need to know everything and we will never give up," Gerry McCann has said.
CNN's Phil Black and Jonathan Wald contributed to this report.