Fans are being urged to only buy tickets from official outlets to guarantee access to tournament matches after it was discovered fake tickets were in circulation.
Any tickets bought from unofficial sources can be cancelled without a refund under Rugby World Cup's ticket terms and conditions.
London Police are working with tournament organisers, England Rugby 2015, and tournament owners, Rugby World Cup Limited, to carry out a full investigation to help ensure that fans are made aware.
World Rugby Chairman, Bernard Lapasset, said: "Fan experience is very much at the heart of what promises to be a very special celebration of Rugby and we urge all fans who are yet to purchase tickets to do so from official channels only or risk being let down.
"With tickets available across official fan, supporter tour and hospitality options, fans should visit rugbyworldcup.com/ticketing to check out the options."
Detective Chief Superintendent Dave Clark, from the City of London Police had a warning for those involved in the selling and distribution of counterfeit tickets, and urged those who have fallen victim to the scam to alert authorities.
"As the National Policing Lead for Fraud we are ready to investigate any suspicious activity around the ticketing market for Rugby World Cup, be it in the production and sale of counterfeit tickets or the supply of tickets that simply do not exist," he said.
"Anyone involved in these practices should not be surprised to receive a knock on their door before, during or after the Tournament. And if you do fall victim to a scam it is very important that you report what has happened to Action Fraud."
With just 17 days to go until the start of the tournament, tickets are still in high demand, with around 50,000 tickets still available for 27 matches, including the All Blacks pool game against Georgia at Millennium Stadium on October 2.
The only official ticket resale programme is available via the website tickets.rugbyworldcup.com.
This is a free to use service for fans that can no longer attend a match to sell their tickets at face value to other fans. This service enables fans to sell to other fans using a safe and authorised platform.
This self-service option keeps fans informed of the status of their tickets with updates throughout the posting and resale process. Fans can log into their account at any stage and withdraw tickets from resale should they change their mind.
Any ticket posted for resale will appear on the official ticketing website, tickets.rugbyworldcup.com, within 72 hours. So far, 99% of the tickets that have been posted have been sold.
