To mark the International Day of Missing Children, a new campaign from European organisation Child Focus has, for the first time ever, depicted the face of a missing child on regular coin.

Designed to "spread the hope for every missing child", from hand to hand and from country to country, the 'Coins of Hope' push will see the face of Liam Vanden Branden, who went missing 20 years ago at the age of two, printed on a million €2 coins by the Belgian National Bank.

The money will be circulated as means of payment as an ordinary coin would, with the idea being that anyone who spends or receives one of these coins will have the chance to "reflect on the fate of all missing children."

A social media initiative is also inviting the general public to post pictures of the coins on Twitter, Instagram and Facebook under the hashtag #CoinsofHope each time the money changes hands.

A supporting website (for which the URL is also printed on the coin) will display the locations of these changeovers, showing how the currency is spreading throughout Belgium and Europe.

For those unable to get their hands on the currency, a tool on the site will let users edit any phone containing a coin into an image featuring one of the special euros.

Child Focus, also known as the European Center for Missing and Sexually Exploited Children, enlisted Wunderman-owned interactive agency These Days to produce the campaign.

Speaking with Creative Social, the founders of These Days, Erwin Jansen and Samuel De Volder, said the project took about one year to build, and that it initially seemed "impossible".

"But we took our shot and Child Focus was really enthusiastic," they added. And now we have a double world’s first: a coin with a missing child’s face on it, and the first coin with an URL on it!"

They continued: "Spreading a message of hope is in itself already very important, making every parent, even everyone, understand that Child Focus and their European counterparts are there to help and that they will never give up.

"And maybe, maybe this could lead to new information which might help to find some answers. To do so, we need help to spread and share our message."