"Pokémon Go," which is currently available in over 30 countries, including the U.S., Canada and much of Europe, was expected to be released in Japan on Wednesday. But, the companies behind the game have decided to delay the launch in the country, a media report said Wednesday, citing a source close to the matter.

Wednesday’s launch of "Pokémon Go" was canceled after internal communication from McDonald's Japan, the game’s sponsor, containing launch details leaked on various internet forums, including 2ch, Imgur and Japan’s Reddit, TechCrunch reported. The morning launch was initially postponed to early afternoon after the details went viral. However, the companies later decided to cancel Wednesday’s launch due to concerns that the hype might overload the game.

While there is no official announcement about when "Pokémon Go" will finally be released in Japan, Nikkie has reported that the game will be made available in the country on Thursday.

Pokémon Go A "Pidgey" Pokemon is seen on the screen of the Pokemon Go mobile app, Nintendo's new scavenger hunt game which utilizes geo-positioning, in a photo illustration taken in downtown Toronto, Ontario, Canada, July 11, 2016. Photo: REUTERS/Chris Helgren/File Photo

John Hanke, CEO of the game's developer Niantic, told Forbes last week that the company needed to ensure that Japanese servers are well-equipped to cope with the huge demand that will follow the game’s launch there.

"Pokémon Go" has generated extremely high demand all over the world, causing servers to crash. After the game was launched in Canada on Sunday, its servers were severely overloaded within an hour of the Twitter announcement.

Meanwhile, Nintendo's shares were down 10 percent in afternoon trade Wednesday following reports that the launch of "Pokémon Go" in Japan has been delayed. The stock, however, has still gained 87 percent since the July 6 launch of the game in the U.S., Australia and New Zealand, boosting the company's market value by more than $7 billion.

Shares of Japan's McDonald's Holdings rose 8 percent after TechCrunch reported Wednesday that the fast-food chain operator would become the first sponsor of "Pokémon Go." The report also said that as part of the sponsorship, McDonald's 3,000-plus fast-food restaurants across Japan will become "gyms" for Pokémon collectors.