Sam Reeves and John Bingham Madeleine McCann asked her mother just hours before her disappearance: "Why didn't you come when we were crying last night?", it was revealed yesterday.

The three-year-old's stark question emerged amid leaked passages from police interviews given by Kate and Gerry McCann just after their daughter's disappearance in Praia da Luz, Portugal, last May.

The couple, in Brussels yesterday to launch a bid for a Europe-wide missing child alert system, were angered by the timing of the leak and were convinced it was a "blatant" attempt to smear them.

They called for the Portuguese Justice Ministry to launch an internal investigation into the revelations, which would be a serious breach of the country's strict judicial secrecy laws.

One furious friend said: "The minute that you talk about Madeleine crying is the minute that the vultures will pile in, that's why this has been leaked." Madeleine, who disappeared just days before her fourth birthday, went missing from the McCanns' holiday apartment on the night of May 3 while the couple were eating tapas with friends nearby.

In her first interview with Portuguese detectives, Mrs McCann spoke about a conversation she had with Madeleine just that morning.

"While we were having breakfast, Madeleine said, Mum, why didn't you come when we were crying last night?'," she told police.

She added: "Gerry and I talked about it for several minutes and decided to watch over the children more carefully at night." Friends of the McCanns said yesterday that the couple had been "puzzled" by Madeleine's remark as she had not apparently been crying when they called in for regular 20-minute checks from the restaurant across the pool.

They said that one of the McCanns' friends, Rachael Oldfield, had been in the adjoining flat, on the other side of Madeleine's wall, all evening and had not heard crying. The couple also insist Madeleine was not speaking angrily and they did not take it as a reproach. Her reference to "we" is understood to have referred to Madeleine and her younger brother Sean.

Friends said they now believe the comment could be a clue that an intruder was in the flat on the night of May 2 and briefly disturbed Madeleine and Sean before fleeing. The Policia Judiciaria interviews were leaked through journalist Nacho Abad, who works for Spanish television programme Ana Rosa Quintana.

Clarence Mi-tchell, the spokesman for the McCanns, said: "The very fact that the comment from Madeleine is now in the public domain is entirely because they themselves told the police about it at the time.

"It is more than curious that this comment, taken in isolation and out of context, that has been in the police file for some 11 months, should now emerge on the very day they are in Brussels trying to improve children's welfare and child safety.

"Kate and Gerry have been subjected to leaks and smears from day one and I'm afraid this has all the hallmarks of yet another poor attempt to influence the headlines on the very day they are seeking to achieve some good in Europe."

Mr Abad would not say how he obtained the transcripts, but added that he had been "asking for these statements from the beginning".

The McCanns were in Brussels yesterday urging MEPs to adopt a Europe-wide missing child alert network, similar to the US-style rapid response.