Anheuser-Busch InBev has quietly moved into the digital publishing business with a series of investments in websites that cover beer culture and the rising craft beer industry. But the slow move by the nation's largest brewer into the editorial business is raising conflict-of-interest questions and causing blowback in the boisterous craft beer community.

The complaints began coming last week when it was disclosed that AB InBev took a minority stake in RateBeer, a site that publishes consumer-driven beer ratings and stories on beer culture. The investment, by the brewer's incubator and venture capital unit ZX Ventures, took place in October but only drew notice last week after after it was discovered by another craft beer beer news site, Good Beer Hunting.

ZX Ventures also funds a beer culture magazine called October that was introduced in January by Pitchfork, the music site owned by Conde Nast. (Good Beer Hunting owner and founder Michael Kiser serves as executive editor of October, a point that Good Beer Hunting disclosed in its coverage of AB InBev and RateBeer.)

And AB InBev runs a site called The Beer Necessities, which it describes as a platform that "celebrates beer, helps to unify the industry, and appeals to everyone from new beer lovers to even the most discerning of beer nerds." The projects are aimed at "broadening awareness around beer culture and enhancing the sophistication of beer," said a spokeswoman for AB InBev and ZX Ventures.

Editorial coverage of beer has gained new relevance in the craft beer era. A growing number of people don't just drink beer, but also discuss, dissect and debate brews in online forums dedicated to tracking the nearly endless supply of small beer brands that have flooded the market.

But AB InBev's investments, particularly in RateBeer, have made some ask what role, if any, a big brewer should take in covering an industry in which it also participates. Anheuser-Busch InBev controls more than 40% of the U.S. beer market and has acquired several craft brewers in recent years.

Sam Calagione, founder of craft brewer Dogfish Head, called AB InBev's stake in RateBeer "a blatant conflict of interest" in a blog post on Monday and said he had asked AB InBev and RateBeer to "remove all Dogfish Head beer reviews and mentions on the RateBeer website immediately."

"It just doesn't seem right for a brewer of any kind to be in a position to potentially manipulate what consumers are hearing and saying about beers, how they are rated and which ones are receiving extra publicity on what might appear to be a legitimate, 100 percent user-generated platform," Calagione wrote. "It is our opinion that this initiative and others are ethically dubious and … lack of transparency is troubling."

Asked about those concerns, the AB InBev spokeswoman said the investment won't affect RateBeer's independence or ability to provide unbiased information.

RateBeer Executive Director Joe Tucker, who describes himself as the site's only full-time employee, defended AB InBev's ownership stake in a statement on the site on Friday. The brewer provided the site with the "resources and infrastructure it needs to move forward and develop for the coming technical challenges and opportunities," he said.

"ZX Ventures has the utmost respect for the integrity of the data and the unbiased service we offer to the entire community and industry," Tucker added.

ZX Ventures' investment in the October site is noted in small font at the end of each story.

But beyond Tucker's statement on RateBeer, there is little to inform viewers of AB InBev's role in that site. "We suggested to Joe he put up a comprehensive FAQ on the site which discloses our stake and involvement in the site," the AB InBev spokeswoman said, "which he is developing now."

Harry Schuhmacher, editor and publisher of Beer Business Daily, a subscription-based publication catering to beer wholesalers, criticized the timing of AB InBev's disclosure, questioning why it wasn't made in October. "It's sneaky," he said in a report to subscribers on Tuesday. "And if I've learned one thing about the craft beer industry, sneaky doesn't work."

The AB InBev spokeswoman countered that ZX Ventures, "like many venture capital funds," does not usually disclose its investments.