The British parents who have run an international campaign to find their missing preschooler were declared suspects in the case Friday, their lawyer said, after traces of blood were allegedly found in their rental car.

Kate McCann was named a suspect in the morning when she went to a police station in southern Portugal for her second straight day of interrogation, lawyer Carlos Pinto Abreu said. Her husband, Gerry, who later spent more than seven hours at the same police station, was also declared a suspect, Pinto Abreu told reporters.

"They have not been charged, and the investigation continues," he said without elaborating.

The girl's aunt said police suggested Madeleine McCann, 4, who went missing on on May 3, might have been killed accidentally and offered the mother a plea deal if she confessed.

"They tried to get her to confess to having accidentally killed Madeleine by offering her a deal through her lawyer — 'If you say you killed Madeleine by accident and then hid her and disposed of the body, then we can guarantee you a two-year jail sentence or even less,"' Gerry McCann's sister, Philomena, told ITV news.

Earlier in the day, a police spokesman, Olegario Sousa, confirmed to the Associated Press that police had named a new suspect, but would not say it was Kate McCann, citing privacy laws. He could not be reached for comment later on Gerry McCann.

Under Portuguese law, an "arguido," or formal suspect, is someone treated as more than a witness, but has not been arrested and charged. As such, the person has the rights to legal representation and to remain silent during questioning.The couple strenuously professed their innocence Friday.

The McCanns, both doctors from central England, were on holiday in Portugal with their three children when Madeleine disappeared. On the night of her disappearance, they put the children to bed and then went to dine in a hotel restaurant, but say they returned frequently to check on her and her twin 2-year-old siblings.

Since then, the McCanns have toured Europe with photos of Madeleine, even meeting with Pope Benedict at the Vatican. Celebrities, including J.K. Rowling and David Beckham, have made public appeals that helped the family raise more than $2 million. The money, controlled by an independent auditor, is meant for charities that aid in missing children cases.

Until Friday, suspicion had focused on a British man who lived near the hotel from which Madeleine disappeared and who was the only formal suspect. But police said new forensic tests done on evidence gathered months after the girl vanished found traces of blood in the couple's rental car, according to Justine McGuinness, a spokeswoman for the family.

McGuinness said the police allegations don't add up, since the rental car was not acquired until 25 days after Madeleine's disappearance.

"We will fight this all the way, and we will not stop looking for Madeleine," Gerry McCann wrote on the couple's website on Friday.

Madeleine McCann's disappearance has hit a nerve among millions, who have followed her parents' lives in Praia da Luz, the seaside town where Madeleine disappeared, and where they have stayed since. Photographs of the bright-eyed, fair-haired girl have been posted throughout the world.

The publicity has helped lead to numerous reported sightings of the girl, from as far away as northern Europe and Morocco, amid speculation she might have been taken by an international pedophile ring.

The only formal suspect until now has been Robert Murat, who lives with his mother near the hotel from which the girl disappeared. He has always maintained his innocence. Sousa said Murat's status as a suspect had not changed.