The identity of this kilted boy is one mystery that Inspector Rebus would be hard pressed to solve, while another image shows an early incarnation of a TV timelord, growing up in Glasgow as a chubby-faced lad.

Who would have known they would go on to become one of Britain's top crime authors and Rebus creator Ian Rankin, and Dr Who actor Peter Capaldi?

The two Scots have parted with their most cherished childhood snaps as Barnardo's steps up efforts to recruit foster carers. Other celebrities have also given early photos of themselves, which will be projected on the streets of UK cities, including Glasgow.

Celebrities who have volunteered their snaps include TV presenter Carol Smillie, Dame Helen Mirren and fellow actors Joanna Lumley, Linda Robson, Fay Ripley and designer Bruce Oldfield.

More than 8600 foster carers are urgently needed.

Brenda Farrell, head of fostering and adoption at Barnardo's, said: "Without the right foster family to care for them, many vulnerable children may never experience the love and stability they so desperately need and happy memories will remain a distant dream.

"We are truly grateful that so many household names are helping us to broadcast our plea for foster parents."

One-third of all children in foster care are moved between different families more than twice a year, the charity said.

Rankin said: "My favourite memories were at family weddings, especially the reception afterwards, with everyone 'doing a turn'. I might sing There's A Hole In My Bucket with an auntie or my sister. Relations would have gathered from all over, cementing the sense of family."