AN investigation has been launched after Olympic fans expressed disappointment at the sight of rows of empty seats on the first day of the London 2012 Games.

Organisers were prompted to act after gaps were visible at a number of venues, including Greenwich Park where a third of seats were reported empty, though this may have been because hungry spectators were searching for food after the venue ran out early on.

In contrast, huge crowds lined the streets, where tickets were not required, to watch Mark Cavendish and Team GB compete in the cycling road race.

Culture secretary Jeremy Hunt said the empty seats were "very disappointing" and suggested they could be offered to members of the public.

He added: "I was at the Beijing Games, in 2008, and one of the lessons that we took away from that, is that full stadia create the best atmosphere, it's best for the athletes, it's more fun for the spectators, it's been an absolute priority.

"Locog are doing a full investigation into what happened, I think it was accredited seats that belonged to sponsors, but if they're not going to turn up, we want those tickets to be available for members of the public, because that creates the best atmosphere. We are looking at this very urgently at the moment."

He said a system had been introduced for these Olympics similar to the one used at Wimbledon, where people coming out of the stadium handed on their tickets so the seats could be made available to other people. "So we are trying a lot of innovations, it's a shame this happened, but we are going to do everything we can to make sure we fill up these stadia."