Race organiser Richard Bates has appealed for the return of vital documents after they were stolen by a car thief.
Mr Bates, a town councillor in Haywards Heath, was the organiser of the five-mile fun run held in Stanmer Park, Brighton, yesterday.
But while he put the last-minute touches to the event, a thief broke into his car.
He said: "The wallet contains six months of work - all the information, mapping and contacts I needed for yesterday's event and details I need to organise the next race.
"The thief also smashed my car window and took my phone, credit cards and cash but it's the black wallet folder with all the documents in that I need back most. It's a terrible inconvenience."
More than 200 people took part in yesterday's race which was held in memory of Mr Bates's running colleague Ray Noakes who died last year.
Any information to Sussex Police on 0845 6070999.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article