Madeleine McCann's parents will make an emotional appeal on BBC One show Crimewatch.

Kate and Gerry McCann have not made a direct appeal on British television so far although they appeared on the Spanish equivalent, Los Mas Busoados, last week.

They are due to appear on Dutch television on Thursday as they keep hope and try to reach as many viewers as possible.

"Crimewatch with its large audience is important," said a family source. "We felt the message was out there in Britain and there was no need for individual programmes.

"But now we feel it's more relevant," continued the source, speaking ahead of tonight's show.

It is more than 30 days since the four-year-old was snatched from her family's holiday apartment in Praia da Luz, Portugal.