Friends of the parents of missing Madeleine McCann have been forced to issue a denial over the allegations linking them to the key suspect.

According to Portuguese newspaper Sol, detectives are investigating a possible link between chief suspect Robert Murat and two friends of the McCann family who are key witnesses in the case.

The Sol report said Murat, 33, has been asked by detectives if he knew one member of the group – hospital consultant Russell O'Brien, 36.

It claimed police spoke to Dr O'Brien after it was discovered the pair were both in Exeter days before Madeleine was kidnapped.

Murat spent 10 days in there, arriving back in the Algarve on May 1 - 48 hours before Madeleine was snatched.

Dr O'Brien and his partner Jane Tanner, also 36, moved to a rented home in the city four weeks earlier, it was reported today.

Find Madeleine campaign manager Justine McGuinness denied that either O'Brien or Tanner met with Murat prior to the disappearance of Madeleine.

"It is absolutely not the case that anyone in the party with the McCanns had ever met Robert Murat before they went on holiday."

Miss Tanner was the key witness who saw a man rushing away from the Ocean Club resort carrying a child wrapped in a blanket.

Dr O'Brien told police he saw Murat near the McCann's holiday apartment that night.

He was one of three friends of the couple who confronted Murat two weeks ago in a showdown set up by police.

Dr O'Brien, Fiona Payne and Rachael Oldfield were allowed to challenge Murat's version of events.

Murat insists he met Dr O'Brien only after Madeleine's abduction, when offering his services to family and police.

Madeleine was snatched from her family's holiday apartment in the Algarve resort of Praia da Luz on May 3. Her parents were dining with their friends at a tapas restaurant 50 yards away.