Madeleine McCann (PA

A family who may have seen Madeleine McCann being abducted could provide vital evidence in the search for the missing four-year-old.

The group saw a man walking towards the beach in Praia da Luz while carrying a child at the time Madeleine vanished, exactly eight months ago.

Portuguese police have taken statements from the family, who live in Drogheda, Ireland.

Now detectives hired by Madeleine's parents want to speak to Martin Smith and his family. The Smiths were leaving Kelly's Bar just before 10pm when they saw a man carrying a child 500 yards from the McCanns' apartment.

Kate McCann, 39, raised the alarm about her missing daughter at around 10pm.

The Smiths are thought to have described the man as white and 5ft 7in to 5ft 9in tall.

His top clothing was obscured by the child. That description matches a suspect seen walking away from the apartment at about 9.15pm by Jane Tanner, a member of the "Tapas Seven" group of friends who were on holiday with the McCanns.

She saw a man carrying a child wearing pink pyjamas similar to those worn by Madeleine.

The McCanns' spokesman said yesterday: "Our detectives are being very methodical and I am quite sure that this family will be on their list."

The eight-month deadline means suspect Robert Murat, 34, hopes to be formally cleared today.