Kate McCann's son told her "you hid Madeleine" because of claims made in a book about the case, a libel trial heard today.
Kate McCann told the court in Lisbon that her son Sean confronted her with the claim last year, which came from a claim made in a book about the case.
She said: "Sean asked me in October: 'Mr Amaral said you hid Madeleine.' I just said he said a lot of silly things."
The child had heard about the claims on the radio while travelling on a school bus, she said.
Kate and Gerry McCann were in court in Lisbon as part of their ongoing defamation case against Amaral, a former police chief in Portugal.
He claimed in his book The Truth of the Lie that the McCanns hid Madeleine's body after she was killed in an accident in 2007.
They are suing him for defamation and stand to receive £1m should the court rule in their favour. The book is banned in Britain.
Speaking outside the court, Gerry McCann said it was important to confront "assertions that have gone more or less unchallenged," and implied the real culprit in Madeleine's disappearance was currently "laughing at what has been told in the book; that there was no abduction, that there is no predator out there.
"There is [a killer out there]. And he, she or they may strike again."
The McCanns have spoken previously of their problems with Amaral and his alleged delaying tactics, which they claim are intended to thwart and frustrate them.
The last hearing was cancelled at the last minute when Amaral fired his lawyer inside the court room. A spokesman for the McCanns said they were told Amaral's new legal representative did not use phone or email.