Only one medal remains from the Twickenham 10k run yesterday, after 499 were stolen before the race.

The course organiser is appealing for any information on the whereabouts of the medals after they went missing from outside the White Swan pub early yesterday morning.

Participants voiced their disgust at the theft on Twitter, which included comment from BBC’s Sophie Raworth.

She Tweeted: “Ran the (muddy) Twickenham 10k this morning. Should be wearing a medal..but someone stole them - all 500 of them.”

One Twitter user, Sharon Bradbury tweeted: “Who steals medals AND from a charity run?!” yesterday, following a message from Graeme Brouder, from Lap Challenge, who set-up the race.

Mr Brouder went to set up at the pub on Twickenham riverside at about  6.45am, nipping home quickly to collect his bike at about 7.20am.

He said: “Stupidly I thought that leaving the bananas, race numbers and medals under the marquee would be fine.

“When I cycled back down at 7.40am I found my bag was missing, this bag contained my gear for putting the course up such as tape, cable ties, etc.

“I checked everywhere and figured someone must have stolen my bag in the 20 minutes I’d left the area.”

The event raised money for the charity Sparks, with part of  every runner's entry fee going to charity.

Mr Brouder said: “I’ve since been in touch with all the runners to say that I will buy more medals as I know some of the runners like to get a memento of the race. I’m gutted that these medals have been stolen, my bag I can live with but why steal medals branded with Twickenham 10k – they are of no use to anyone.”

The remaining medal is one that Mr Brouder gave to his nephew, which is pictured.

Anyone with information should contact Graeme Brouder at graeme@lapchallenge.co.uk.

Police are yet to respond.