Sam Marsden

Kate and Gerry McCann were consulting lawyers yesterday after the publication by a former senior Portuguese detective containing allegations against them.

Goncalo Amaral, former head of the investigation into the disappearance of the couple's daughter Madeleine, affirms that the young girl is dead.

His book, entitled The Truth Of The Lie, is published today but excerpts were printed in the Portuguese paper Correio da Manha yesterday.

The McCanns were formally cleared of involvement in Madeleine's disappearance on Monday, when prosecutors lifted their status as "arguidos", or formal suspects in the case. They say they will continue to believe their daughter is alive until given firm evidence to the contrary.

McCann family spokesman Clarence Mitchell said yesterday: "Mr Amaral will face immediate and swift legal action if he in any way implies, either directly or indirectly, that Kate and Gerry were involved in the disappearance or harming of their daughter.

"Beyond that I will not comment. The lawyers will be studying Mr Amaral's book as a matter of some urgency."

In an extract published yesterday Mr Amaral claimed that British police held back potentially important information for six months.

He wrote that information was passed on to Leicestershire Police on May 16, 2007, less than a fortnight after Madeleine disappeared.

But he alleged that the UK force did not communicate the information to their Portuguese counterparts until after he was removed from the case in October.