Soldiers sit in the empty seats held by the IOC as they watch the women's gymnastics qualification in the North Greenwich Arena during the London 2012 Olympic Games July 29, 2012.?[Photos/Agencies]

LONDON - Olympic organisers scrambled on Sunday to quell a scandal over depressing TV images of half-empty stands at the London Olympics as a government minister said an urgent inquiry had been launched to identify just who had failed to show up, and why.

Fans from all over Britain who had been charmed by the Olympic publicity offensive, but were let down by a complex ballot system, were outraged by footage of empty seats at key venues including Wimbledon - one of the hottest tickets in world tennis.

"It's infuriating to see so many empty seats on TV. Surely it can't be beyond the organisers to allow real sports fans to fill them up on a first come first served basis?" said Ed Shorthose, a London-based father of two who has been trying for months to get tickets to see the Games.

More vacant seats were reported on Sunday, the second day of the Games.

Organisers said they were in touch with the International Olympic Committee to discover who failed to show up and why.

A Games official told Reuters it was still unclear whether the empty seats in several events, including Wimbledon, swimming, gymnastics and basketball, had been allocated to sponsors, international federations and athletes' families.

"We are trying to find out who these tickets belonged to," said the official.

British Olympic Association Chairman Colin Moynihan told a briefing on Sunday one solution might be a 30-minute rule whereby fans would be allowed to take up vacant seats if spectators were late or did not arrive.

Sunday no-shows

Moynihan said the search was on for who had not taken up tickets. "Where you have large blocks of seats you can pretty quickly know," Moynihan said.

Spectators reported more empty seats on Sunday.

"We've got a few empty seats, so please shout twice as loud for those empty ones," announcer Ian Oswald said at one men's weight-lifting event.

More empty seats were reported at the women's gymnastics, particularly close to the mat. Soldiers, apparently who had been on security duty, occupied some of the empty chairs.

Seats were also vacant at the eventing dressage despite the appearance of Zara Phillips, Queen Elizabeth's grand-daughter, who is part of the British team.

Culture Secretary Jeremy Hunt, the minister responsible for the Olympics, said he was disappointed by the empty seats and that the London Organising Committee (LOCOG) were looking into it.

"LOCOG are doing a full investigation into what happened," Hunt told publicly funded broadcaster BBC after a widely praised surreal and exuberant opening ceremony starring the queen, Paul McCartney and Rowan Atkinson.

"We think it was accredited seats that belong to sponsors, but if they are not going to turn up, we want those tickets to be available for members of the public, because that creates the best atmosphere. So we are looking at this very urgently at the moment," Hunt said on Saturday.

Sports Minister Hugh Robertson said he was surprised that the events were not full.

"Sold out"

LOCOG became used to putting up the "sold out" sign within minutes of each tranche of tickets going on sale to the public.

On Saturday some ticket box offices at venues in the park still had queues of people seeking to buy tickets for selected sports.

LOCOG declined to provide a figure for the number of people in the park on Saturday or how many tickets had been sold but said that 11 million people would attend the Games.

By early June, 7 million of the total 8.8 million Olympic tickets had been sold, and about half of the 2.45 million Paralympic tickets, in a process that began last year.

But the combination of a complex and opaque online ticketing system which appeared unable to cope with the huge demand and seemed skewed towards those prepared to bid for thousands of pounds worth of tickets, resulted in a wary public.

About a quarter of the 928,000 tickets made available in May failed to sell, including for popular sports such as beach volleyball and boxing.

In early June, LOCOG still had about 550,000 tickets to sell with just weeks to go.

A large chunk of them were so-called contingency tickets which had been held back while logistics such as TV camera positions were resolved.

Jin Horne, a 29-year-old financial analyst in London's financial district, said on her way into see the gymnastics on Sunday morning that she could not get tickets for her friend visiting town.

"I heard my company had loads of tickets but they were only for very important people," she said.