Lisbon (AFP) - British police investigating the disappearance of three-year-old Madeleine McCann were in Portugal Tuesday to help question suspects and witnesses, local media reported.
Four people are set to be placed under investigation in the coming days and eight others are set to be questioned as witnesses, according to the Correio da Manha and Diario de Noticias newspapers.
One of those being placed under investigation is thought to be a man of Russian origin who has already been the subject of investigations by Portuguese police after Madeleine's disappearance in May 2007.
Portuguese prosecutors and Scotland Yard would not immediately comment on the reports when contacted by AFP.
Madeleine disappeared from a bedroom of her family's holiday apartment in the Algarve resort of Praia da Luz a few days short of her fourth birthday as her parents dined with friends at a nearby tapas restaurant.
Most of those questioned by police so far are former employees of the hotel complex, Portuguese media has reported.
The Portuguese investigation into Madeleine's disappearance was wound up in 2008.
But British police re-examined the evidence and opened their own investigation in July last year, closely followed by the Portuguese authorities.
Last month, Portuguese and British investigators conducted an eight-day search of patches of land around Praia da Luz but found no evidence relating to her disappearance.
Seven years on, Madeleine's parents Kate and Gerry McCann have never given up hope of finding their daughter alive.