British police investigating the disappearance of three-year-old Madeleine McCann are back in Portugal to help interview key suspects.
Gerry and Kate McCann say they will continue to pursue their libel case against a former Portuguese police officer.
Kate & Gerry McCann are at the libel trial of a former police chief, who claimed the couple were involved in their daughter's disappearance.
The questioning of four suspects is due to begin in Portugal, as part of the Madeleine McCann investigation.
ITV News Correspondent Neil Connery is in Faro:
British Police have arrived at Faro police station, as officers are set to question four suspects in connection with the disappearance of Madeleine McCann.
ITV News Correspondent Neil Connery is in Portugal:
British police arrive at Faro police station as questioning of four suspects in McCann case due to begin. http://t.co/xSTaCZcvlI
Dci Andy Redwood and colleagues investigating McCann case arrive with folders to Faro police station. http://t.co/s2FuHtgcM8
Scotland Yard is to begin questioning four formal suspects in the investigation into the disappearance of Madeleine McCann, ITV News understands.
Officers will begin questioning the four people - identified as arguidos, meaning formal suspects - tomorrow at a police station in Faro, Portugal.
Eight key witnesses will also be questioned.
The three-year-old vanished while holidaying with her parents in Praia da Luz in 2007.
Kate and Gerry McCann said they were exasperated and disappointed by the further delays to their libel trial against former police officer Goncalo Amaral.
Speaking outside court, Gerry McCann said the delay was a "blatant and cynical attempt" to wear them down, and the delays are an injustice to their daughter.
Kate McCann said the delays add more pain and distress to the family, which is why they took the case against the former police chief in the first place. The couple said they would not give up looking for their daughter, and would continue their fight against Mr Amaral an her behalf.
Kate and Gerry McCann said there was "no evidence" their daughter Madeleine was dead. Speaking to reporters outside a court in Lisbon, the McCanns said their daughter "deserved justice."
Kate and Gerry McCann traveled to Lisbon to testify against Goncalo Amaral, the former police officer in charge of the hunt for their missing daughter.
They are suing Mr Amazal for libel over the claims he made in his book The Truth Of The Lie, which included suggestions that they hid Madeleine's body after she died in an accident.
But Mr Amaral delayed the court case by sacking his legal team this morning, just hours before the trial was meant to wrap-up.
The parents of Madeleine McCann, the British girl who went missing in Portugal in 2007, have arrived in Lisbon to tell a court how accusations made against them in a former police chief's book have affected them.
Kate and Gerry McCann say Goncalo Amaral have caused them unnecessary grief.
The McCanns are suing Mr Amaral for libel over the claims he made in his book The Truth Of The Lie.
Their appearance will mark the end of the trial, but a final ruling on the case is not expected until later this year.
Their then four-year old daughter Madeleine disappeared from a holiday apartment in Praia da Luz in the Algarve in May 2007.
Claims in Mr Amaral's 2008 book included suggestions that they hid Madeleine's body after she died in an accident.
The McCanns say the book damaged the hunt for their daughter and exacerbated their anguish.
Kate and Gerry McCann have released a statement via their official Facebook page, in which they say they are 'pleased' by the police activity in Portugal and are thankful for their efforts:
We are very pleased that significant activity has taken place in Praia da Luz over the last 8 days with police officers and support teams from the UK working closely with the Policia Judicial and the Guarda Nacional Republicana...
...We are further encouraged that, despite the intensive searches, no trace of Madeleine has been found and this reinforces our belief that she could still be alive...
...As parents of a missing child, we have always wanted all reasonable lines of enquiry to be followed and it is gratifying to know that a substantial amount of work will take place over the coming months with close cooperation of the British and Portuguese authorities...
...We would like to thank all those involved for their efforts and the members of the public who have come forward with information.