Some 3,000 Olympics tickets from international sports federations were "put back in the pot" on Sunday night and sold to the public, Locog have said.
The move came after the sights of swathes of empty seats at events in the first days of the Games prompted anger from people who had struggled to get tickets.
London 2012 chairman Sebastian Coe had promised to urge international federations to make sure they used areas reserved for them to avoid embarrassment. Jackie Brock-Doyle, Locog's director of communications, said they had been able to get back 3,000 and re-sell them - a move they will do each day to make sure as many seats as possible are filled.
"We talked to the International Federations, we were able to put back into the pot for sale around 3,000 tickets, they have all been sold," she said.
"That includes about 600 for the gymnastics event and we're going to do that on a day-to-day basis."
She said they were talking to accredited groups, including broadcast media and seeing if they can release some tickets.
"Where we can we are going to release those the night before and put them up for sale," she added.
"Three thousand went up for sale and they have all been sold."