Kate and Gerry McCann have instructed their lawyers to demand a website which claims their daughter was not the victim of kidnap to be removed.
The Madeleine Foundation claims Madeleine was not abducted from her apartment in Praia de Luz, that she is dead and that Kate and Gerry bear some responsibility for her death.
The foundation, in a statement on its website, says libel specialists Carter-Ruck have insisted they hand over all remaining copies of leaflets and booklets they have published to support their claims against the McCanns.
Spokesman for the McCann family, Clarence Mitchell said: "Kate and Gerry have consistently made it clear they will not dignify the actions of the so-called Madeleine Foundation with any comment whatsoever.
"However Carter-Ruck's position is now clear and it is in the hands of Kate and Gerry's defamation lawyers."
The statement on the foundation's website states they were given until Friday to reply to Carter-Ruck's letters and were now taking legal advice.
Madeleine's disappearance from the Ocean Club in Praia da Luz, at the age of three, made worldwide headlines and continues to provoke huge public sympathy and concern worldwide.
Dr McCann, 40, and his Liverpool-born wife Kate, 41, set up findmadeleine.com fund to aid the hunt for Maddy raised more than £1.5m but, despite extensive enquires and many alleged sightings, she is still missing.
on2u, USA around 4 months, 4 weeks ago