An urgent investigation has been launched after the sight of rows of empty seats on the first day of the London 2012 Games caused outrage among many Olympic fans who had missed out on tickets.

Organisers have been forced to act after gaps were visible at a number of venues, including the Aquatics Centre where British medal hope Hannah Miley missed out on a podium place.

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 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."

London 2012 chairman Lord Coe has previously threatened to name and shame companies which do not use their tickets.