The parents of missing Madeleine McCann marked three months since her disappearance as a possible sighting of her emerged in Belgium.
A customer at a restaurant in the Flemish town of Tongeren, not far from the Dutch border, said she was "100% sure" she had seen the youngster.
She said the girl was with a couple, a Dutch man and an English-speaking woman, who were acting strangely and not like "normal parents". A police spokeswoman said they were treating the report "seriously" and are looking for DNA on a drinks bottle used by the girl.
They have also issued an identikit drawing of the man based on the description given by the "trusted witness". It is the latest in a string of possible sightings since Madeleine disappeared in May, although none have turned into concrete leads.
As news of the Belgian sighting spread across the continent, her parents Gerry and Kate McCann were travelling to Spain to mark the three months since her abduction. From their base at Praia da Luz in Portugal, they will travel to Huelva, the capital of Andalucia, and put up posters of the four-year-old across the city.
Police in Belgium were first alerted on Saturday after the customer at the De Pauze restaurant noticed a girl fitting Madeleine's description. The woman, a child therapist, said the couple with her did not seem to be acting like a mother and father, and told a waitress, Jolien Houbrech.
Miss Houbrech said: "A woman who was a child therapist came up to me and asked if I noticed any resemblance between Madeleine and the child. She said that because of her work as a child therapist she had noticed that the people's behaviour was not that of normal parents. After she said that, I said maybe she should call it in to the police."
Miss Houbrech, a 21-year-old student, said the child had long blonde hair down to her shoulders and was aged around five or six. The couple, who were driving a Volvo estate car with a Belgian number plate, left before the customer had raised her concerns, she added.
A Belgian police spokeswoman said: "We had a witness who possibly saw Madeleine McCann. She was accompanied by two people - a man and a woman. She was 100% sure it was Madeleine and it is a trusted witness. She works with children and noticed something unusual, that is why we are taking it seriously."
The spokeswoman added that results from the DNA tests were expected next week.
