By Michael Bristow
BBC News, Beijing
Black market tickets for next year's Olympic Games in China are already being sold illegally on the internet.
China will eventually sell seven million tickets for the Games
Individuals who were initially allowed to buy 50 tickets each are cashing in by selling them for more than 10 times their face value.
Beijing's Olympic Committee (BOCOG) allows tickets to be transferred between users, but not for profit.
The second round of ticket sales has just been launched, and applicants will be randomly allocated seats.
A BOCOG spokesman said: "We will work with relevant departments to respond to the practise of reselling tickets for profit."
More than 1.5 million tickets were allocated in the first round of ticket sales, which was only open to people living in mainland China.
Some of those who secured tickets in this round are now advertising their unwanted seats on Chinese websites.
Tickets for the opening ceremony on 8 August are on sale for as much as 39,000 yuan ($5,270, £2,600). Their face value is just 3,000 yuan.
Customers have been eagerly queuing for tickets
Seats for a wide range of events are being advertised, including events that are likely to be seen as highlights of the Games.
Tickets are available for the 110m hurdles final, in which Chinese athlete Liu Xiang won gold in Athens in 2004. He was the first Chinese man to win a track and field gold at an Olympic Games, and his appearances regularly attract big crowds.
Individuals who have been allocated tickets will not be given them until next summer, but this has not stopped people selling them beforehand.
Some buyers and sellers are signing contracts that promise tickets will be handed over immediately after they are issued.
The BBC bought two tickets for two badminton semi-finals from a man who insisted we sign a contract giving transaction details.
He charged a total of 2,000 yuan ($270, £133) for two tickets that cost him just 600 yuan. We paid a deposit of 600 yuan, with the remainder to be paid when we get the tickets.
These sales are being carried out despite a ban on speculation. There was a similar ban in Athens in 2004 and Sydney in 2000.
At a recent press conference, Zhu Yan, director of the Beijing Olympic Ticketing Centre, said: "We prohibit the resale of tickets."
"If people want to transfer a ticket to someone else, that is OK, but you cannot resell it for profit," he added.
People who flout this rule face 10-15 days detention and a fine of 1,000 yuan, according to state media.
The large stockpile of black market tickets is perhaps the result of allowing people to buy up to 50 tickets each in the first round of sales.
That number is being reduced to just eight tickets in the second round, which will be open for applications from December 10-30.
BOCOG officials say they reduced the number of tickets each person can buy to give more people the chance to watch an Olympic event.
But preventing them being resold for a quick profit was another reason for the change.
The International Olympic Committee (IOC) says it is up to the Chinese authorities to prevent people from making money by reselling tickets.
It says the Chinese have the means to do this because each ticket has a tag that identifies the initial buyer.
"Given that the tickets can be tracked down, we hope this will deter people from selling them on," said IOC spokeswoman Emmanuelle Moreau.
BOCOG says it has already introduced systems to help it prevent the resale of Olympic tickets, but at the moment they do not appear to be working.