The Metropolitan Police has called for regulation or potential new laws to combat ticket crime - including fraud, counterfeiting and touting - in a new report.
Apart from the resale of football tickets, reselling tickets is not illegal, but the force has called for a clampdown on ticket crime after tackling it during London 2012.
Ticket fraud alone costs around £40 million a year, the Met said.
In the report, the force called for a transparent ticketing market underpinned by either regulation, legislation, or both, to help people understand who they are buying from and therefore better protect themselves against ticket crime.
The report also called for victims of ticket crime to report suspected offences to the authorities and agencies such as Action Fraud. That will allow the police and other authorities to gain a more accurate picture of the scale of ticket crime and then take action to stop it.
The Met also said the ticketing industry needs to build relationships with search engine companies, website hosts and registrars and the payments sector to help tackle ticket crime. The force also wants to make it easier to suspend fraudulent websites.
During Operation Podium, the Met worked on tackling economic crime around London 2012 and has published this report - Ticket Crime: Problem Profile - as a result of learning from that experience.
Detective Superintendent Nick Downing, who leads Operation Podium, said: "Experience shows that fraud is the most prevalent form of ticket crime and causes the greatest harm - conservatively estimated at £40 million per year. Criminals involved in this are also highly likely to be involved in other crimes.
"We also know that it is extremely under reported, and there is a lack of public awareness and understanding which means that people find it difficult to distinguish between an authorised, unauthorised or fraudulent websites. For these reasons it is important that ticket crime is properly tackled and the awareness is raised on how the public can take steps to protect themselves from becoming a victim of these crimes."
Jonathan Brown, on behalf of the Society of Ticket Agents and Retailers (STAR) and its members said: "This industry has never before benefited from such concentrated work to help uncover criminality and fraud which continue to cause detriment to the ticket buying public. We are grateful for the support from Operation Podium during the launch of STAR's kite mark for identifying authorised ticket sellers in 2011."