A consultant in acute medicine at the Royal Devon and Exeter Hospital, he knew Gerry McCann from Leicester.

He was on holiday with his partner Jane Tanner and their two young daughters.

At 9.25pm he left the restaurant for around 25 minutes to check on one of the girls, who was ill.

He has been subject to a vicious Portuguese press campaign alleging he was absent for over an hour when Madeleine went missing. He has threatened to sue, insisting: "These reports are completely untrue and extremely hurtful."

Jane Tanner, 37

Dr O'Brien's partner. She arrived late at the tapas bar after treating their sick daughter.

On the way, she passed the McCanns' apartment and saw a man carrying a child. Crucially, her description of the child's clothes matched Madeleine's pink pyjamas.

Dr Matthew Oldfield, 37

Dr Oldfield, an endocrinologist at Kingston Hospital in South-West London, went to check the McCann children at 9 25pm.

But he did not look inside the flat - simply listened from outside to ensure Madeleine and the twins were not crying.

Rachael Oldfield, 36

Dr Oldfield's wife, a former lawyer who is now a recruitment consultant.

She is one of four witnesses who claim to have seen the first suspect, British expat Robert Murat, near the McCanns' flat.

Last month she angrily dismissed reports that police had intercepted phone calls and emails between the McCanns and their friends which contradicted the group's earlier statements.

Mrs Oldfield accused Portuguese police of "throwing mud when we are not able to defend oursleves"

David Payne, 41

Mr Payne is a senior research fellow in cardiovascular sciences at Leicester University

He and his wife and mother-in-law joined the group at 8.55pm.

They are believed to have been the only ones using a baby monitor to check on their two children.

Mr Payne has said: "All these smears and rumours are overshadowing the important thing, which is to get Madeleine back."

Dr Fiona Payne, 34

Mr Payne's wife, she is understood to have told police she saw Mr Murat shortly after Madeleine vanished.

Dr Payne and her husband stayed on in the Algarve to support the McCanns. When the couple were made official suspects, she said: "It's an outrage - a preposterous accusation."

Dianne Webster

Dr Payne's mother. She has given no public interviews.