London 2012 organisers are setting up a website checker to allow ticket buyers to verify if the seller is genuine.
UK residents should apply for tickets via the London 2012 website and every country has its own authorised outlet.
But organisers and police are concerned hundreds of bogus websites will spring up when tickets go on sale on 15 March.
More than 30 people have been arrested so far in connection with alleged ticket scams related to the Games, Metropolitan Police have said.
Paul Deighton, chief executive of the Games organisers Locog, said a website checker would be in place by the time tickets go on sale next month.
Users will be able to paste the URL of a site into a box to find out if it is genuine.
If the site is fake, they will be redirected to the correct ticket seller for their country.
The Metropolitan Police has a specialist unit dealing with the threat of organised ticket fraud at the Olympics, including bogus websites, fake tickets and touting.
Operation Podium has launched nine operations and made 32 arrests since being set up in June 2010.
Detective Chief Inspector Nick Downing said: "Any criminal looking to exploit the Olympic economy will come on our radar, we will be watching them and we will target them."
Mr Downing said Operation Podium had compiled a list of "hundreds, moving to thousands" of touts who would be monitored in the run up to the Games.
Many of them were persistent operators who had previously targeted the Football World Cup in South Africa, Winter Olympics in Vancouver and the Beijing Olympics.
He added: "We don't believe this is low-level touting, it's organised crime with a business model and we are looking to disrupt that business by seizing assets."
Locog is also in discussion with eBay and all the big UK auction sites to stop tickets being resold there.
Under Section 31 of the London Olympic Games and Paralympic Games Act 2006, it is illegal for organisations to offer tickets for sale unless authorised by Locog.
It is also illegal for individuals to sell tickets for profit and the offence carries a maximum £5,000 fine.
A spokesperson for eBay confirmed that the company was working closely with Locog "to ensure tough and effective filters are in place to identify and remove such tickets if anyone attempts to sell them".
Mr Deighton said London 2012 organisers would provide a system for people with unwanted tickets to resell them legitimately.
He said: "People will be able to resell through us at face value. It will be very simple, very clear, very efficient.
"You won't get stuck with a ticket if you find you can't go."
He added: "We are focussed on getting the tickets into the hands of the genuine fans.
"If you get a cycling ticket into the hands of a cycling fan, he's not going to let go of that easily."
The Games will see more than 600 sessions of Olympic competition across 26 sports.
Some 8.8 million tickets will be issued with three-quarters of them going on sale to the general public between 15 March and 26 April 2011.
A further 12% will be issued to National Olympic Committees (NOC) of each country and the final 13% will be split between sponsors, the IOC, guests and hospitality partners.
In the past, a significant amount of unauthorised reselling has involved NOC-allocated tickets.
For London 2012, each country's ticket allocation will be based on the sports in which they excel or have a strong following for.
The action starts on 25 July with women's football in Cardiff, Coventry, and Glasgow, two days before the official opening ceremony.