Kate and Gerry McCann took part in an event yesterday to mark International Missing Children’s Day alongside relatives of Katrice Lee, from Hartlepool, who was two when she vanished in Germany more than 27 years ago.

The couple spoke of how they could not bear to meet other families in their situation in the days and weeks after Madeleine vanished from Portugal in May 2007, but now drew strength from sharing their experiences.

Sitting next to Katrice’s sister Natasha and mother Sharon, Mrs McCann said: “It’s easy to meet families where the children have been found because that gives you hope.

“But, obviously, emotionally it is quite difficult to put yourself in a situation where a child has been missing for years and years.

“Obviously now it is easier, and I have to say it’s been a comfort.”

Her husband added: “Early on Kate and I couldn’t even entertain the idea of speaking to another family whose child was still missing, particularly for a long time, because you think, ’I just hope we don’t get there’.”

The McCanns also revealed they have been supported by letters from other relatives of missing children, including the family of Daniel Morcombe, who was 13 when he disappeared from the Sunshine Coast in Queensland, Australia, on December 7, 2003.

Mr McCann said speaking to the Lee family was especially helpful because of the common threads in their situations.

The Lee family were based in Germany with the British military when Katrice disappeared from a Naafi shopping complex in Paderborn, Germany, on November 28, 1981.

Mr McCann said: “What they have gone through is very similar, and the whole experience is similar, particularly the barriers that they faced.

“And an abduction in a foreign country adds a different dimension to everything that you face.”

The McCanns, from Rothley, Leicestershire, also met Nigel Greenhalgh, uncle of Damien Nettles, who was 16 when he went missing after a night out with friends in Cowes on the Isle of Wight on November 2, 1996.

Mrs McCann made a heartfelt plea for the public to continue thinking about missing children even after they slip out of the media.

She said: “It’s devastating that it has to be when a child goes that the interest comes back - what can be more important than children?”

The event on London’s South Bank heard from experts who spoke of moves to improve information sharing about missing children across the UK and around the world.