Volunteers working at the London Olympics have been warned not to give away breaking news about athletes or disclose the location of politicians and celebrities through online comments or pictures posted on social media sites.

Organizers are in the process of recruiting 70,000 unpaid volunteers to help run the Games from July 27-August 12.

Britain said last month that it would provide up to 13,500 troops to protect the Games after organizers said security needed to be doubled. As well as the athletes, many world leaders traditionally visit the Games at some point.

Organizers are also keen to ensure that sponsors who help to fund the Olympics are the only companies able to market their brands at venues.

A spokesman for the London Organising Committee said that security was one concern, but that it was normal for organizations to explain how workers should use social media.

We understand that many of our Games Makers (volunteers) will want to use social media to share their exciting experiences at London 2012 with their friends and family, the spokesman said.

As is standard in most organizations, we have provided some practical guidelines to give basic advice on interacting in a social media environment with the aim of protecting the interests of our workforce and operation, he added.

(Reporting by Keith Weir)