Olympic organisers have blamed spectators using Twitter for disrupting television coverage of the cycling road races. Viewers were left in the dark about timing and positions after electronic updates failed to reach commentators during both the men's and women's events.

The BBC blamed the Olympic Broadcasting Service (OBS) for the lack of information which left commentator Chris Boardman using his own watch to estimate timings. But the International Olympic Committee said fans sending updates to Twitter while watching the race had in effect jammed transmissions of race information.

Communications director Mark Adams said: "From my understanding, One network was oversubscribed, and OBS are trying to spread the load to other providers. We don't want to stop people engaging in this by social media but perhaps they might consider only sending urgent updates."

The timings are sent to organisers via tiny GPS transmitters in competitors' bikes but the messages were not being received during the races.

A spokeswoman for Games organisers Locog said: "There are fixed timing points at the start and finish line, as well as one at Box Hill which Locog provides. These worked well and the result and timing of the race are not in doubt."