One of the key witnesses in the Madeleine McCann inquiry, Dr Matthew Oldfield, is a consultant endocrinologist at Kingston Hospital.

Reports in the national press said that Dr Oldfield and his wife, Rachael, a recruitment consultant, were dining with the McCanns at the resort in Praia da Luz on May 3, the night their daughter went missing.

Reports say Dr Oldfield was the last to check on Madeleine before her mother discovered her to be missing at 10pm.

In his statement to police, which was not officially released but was leaked to newspapers, he allegedly admitted only listening at the door or just popping his head round, sparking speculation she may have gone missing before 9.30pm.

Dr Oldfield is a consultant endocrinologist who works for Kingston Hospital.

He had worked with Gerry McCann at a Leicester Hospital before moving to London.

National press reports said he was one of three witnesses brought forward by Portuguese police to a meeting with Robert Murat, over discrepancies in witness accounts.

He allegedly told them he had seen Mr Murat near the apartment. But Mr Murat said he was in all night.

Colin Todd, medical director at Kingston Hospital NHS Trust, said: "We can confirm that Dr Matthew Oldfield is a consultant at the trust and has been in employment here since 2004.

"This is a private matter for Dr Oldfield, and the trust will not be making any further comments on this matter."