Madrid, Spain (CNN) -The parents of missing Madeleine McCann are due in Portugal this week as plaintiffs in a case seeking 1.2 million euros ($1.7 million dollars) in libel damages against a former Portuguese police investigator, McCann family spokesman Clarence Mitchell told CNN.
The ex-officer, Goncalo Amaral - who worked for a time on the case after Madeleine was reported missing in May 2007 - wrote a book that "indirectly alleges Madeleine is dead and implies" the parents must have known, Mitchell said.
Madeleine vanished from the family's holiday villa at the Portuguese beach resort of Praia da Luz on May 3, 2007 as her parents, Kate and Gerry McCann of Britain, dined in a nearby restaurant. She was 3 years old at the time.
The McCanns maintain that Madeleine is alive and have garnered international support in an effort to find her, enlisting the aid of celebrities and Pope Benedict XVI.
Kate and Gerry McCann are due to fly to Lisbon Monday afternoon and plan to attend the full hearing, which starts Tuesday and is expected to last three or four days. A verdict is likely soon after the conclusion, possibly by the end of next week, Mitchell said.
The McCanns accepted $1.1 million in libel damages in March 2008, and front-page apologies from the London newspapers the Daily Express and the Daily Star, over stories alleging the parents were involved in the disappearance or death of their daughter.
The money went to Madeleine's Fund, a nonprofit company set up to find the girl and bring to justice anyone who played a role in her disappearance.
At one point, authorities in Portugal had named the girl's parents as suspects, along with a British man living in Portugal, Robert Murat. But a spokesman for the Portuguese prosecutor's office said in July 2008 that authorities found no evidence of involvement by any of the three and were no longer considering them suspects.
Portuguese investigators closed the case in July 2008.
Amaral's book, "A Verdade da Mentira," ("The Truth of the Lie") was published in Portugal in 2008.
It has since been published in France, Germany and Spain, with excerpts and its allegations repeated on the Internet, Mitchell said.
A Portuguese judge has granted an injunction against Amaral, freezing some assets, and ordering him not to repeat his allegations. The judge also ordered unsold copies of the book to be returned to the publisher, and "many thousands" have already been returned, Mitchell said.
But Antonio Cabrita, a lawyer for Amaral, told CNN he will argue the right to "freedom of speech," under the Portuguese constitution in seeking to lift the judge's injunction against the book and Amaral.
The injunction, issued in September 2009, also extends to the book's Portuguese publisher and a Portuguese TV station that reported on the book's allegations, said Cabrita, who represents only Amaral, not the other defendants.
Amaral is expected to testify first, on Tuesday, about his book's allegations that Madeleine may have died accidentally at the Portuguese resort and that her parents were aware of that, Cabrita said.
"Now there is a chance to present new facts" to the judge, Cabrita said, adding that Amaral's book basically contains allegations that were part of the police investigation before authorities closed the case.
Mitchell said such allegations, which can't be proven, hurt the parents' search to find Madeleine.
The McCann couple "didn't start this fight" with Amaral and were reluctant to bring the lawsuit, but felt compelled because "he can't prove his points," Mitchell said.
Amaral was a lead investigator on the case when he gave an interview to a Portuguese newspaper, despite an order of judicial secrecy surrounding the investigation, and his superiors then removed him from the case, Cabrita said.
CNN Madrid Bureau Chief Al Goodman contributed to this report
From Sky News
McCanns Return To Portugal For Libel Case
11:05am UK, Monday January 11, 2010
Neal Walker, Sky News Online
Kate and Gerry McCann will return to Portugal later for the libel trial of the former policeman who led the investigation into their daughter's disappearance.
The McCanns say any damages they are awarded will fund private investigators
The couple launched legal action against former Portuguese detective Goncalo Amaral after he published a book questioning their account of what happened to Madeleine.
Mr and Mrs McCann, from Rothley, Leicestershire, will fly to Lisbon today ahead of the three-day trial, which is due to start at the main civil court in the Portuguese capital tomorrow.
The couple plan to attend all the hearings, but do not intend to go back to the Algarve resort where Madeleine vanished more than two-and-a-half years ago.
Family spokesman Clarence Mitchell said: "I can confirm that Kate and Gerry McCann will be returning to Portugal on Monday to attend the resumption of the Amaral trial on Tuesday.
"The details of their travel plans and itinerary will remain private at their request."
Madeleine was nearly four years old when she went missing from her family's holiday apartment in Praia da Luz in the Algarve on May 3, 2007, while her parents dined with friends nearby.
Four months after her disappearance, Mr and Mrs McCann were made 'arguidos', or formal suspects, but this was lifted when the investigation was shelved in July 2008.
Mr Amaral led the investigation in the first six months following Madeleine's disappearance.
But he was taken off the case in October 2007 after criticising the British police in a newspaper interview.
n his book Maddie: The Truth Of The Lie, which was published in July 2008, Mr Amaral claimed that Madeleine was dead, and questioned the McCanns' account that she was abducted.
A Portuguese judge granted an injunction in September last year banning further sale or publication of the book.
The former policeman was also prohibited from repeating his claims about Madeleine or her parents.
The McCanns travelled to Lisbon for the opening of the libel trial in December, but the hearing was adjourned until this week after Mr Amaral's lawyer failed to turn up for health reasons.
The couple have previously said any money awarded in damages by the courts would go towards paying for private investigators to look for their daughter.
Sky News Online will be covering the libel case with line-by-line live updates from inside the courtroom in Portugal.