Capcom is investigating reports that copies of Resident Evil 6 have been sold over one month in advance of the game's official release date.

A Polish website reported yesterday that it had been able to purchase a PS3 copy of Capcom's upcoming survival horror from a store in Poznan, Poland.

The site posted images alleging to be of the game's box, disc and manual, as well as in-game shots to back up its claim.

The game isn't officially due to go on sale until October 2.

"Noted guys," Capcom COO Christian Svensson said in response to a thread on the publisher's community website pointing out the broken street date. "We are investigating. Thanks for your concern."

In a second thread, Svensson confirmed that the North American release date "remains 10/2".

NeoGo, the site that reported the leak, has continued to post evidence of its purchase following its initial report.

The website has since posted a video showing the game's opening and additional photos of the game's manual.

"We do not plan to spoil the entire game," NeoGo said on its YouTube channel.

"Neo Plus magazine collaborates with games publishers and respect their embargos. Enjoy the taste, however - it REALLY is RE6 and it REALLY works."

If true, the early leak could harm sales of Resident Evil 6.

A post on industry forum NeoGAF suggests that the game has already made its way onto piracy websites.

A supposed copy of the game has also appeared on eBay. The seller is asking for a minimum of 2.000,00 Polish Zloty (£380 GBP).

Capcom announced that Resident Evil 6 had gone gold last week.