Shareholder lawsuits are common. Here’s what makes the one at Tree House Brewing unique.

A civil complaint filed this month in Hampden Superior Court accuses the two controlling owners of Tree House of placing their own interests over those of people who own smaller stakes in the Charlton-based business.

Eric Granger, a 2 percent owner and Tree House’s last remaining minority shareholder, alleges that chief executive Nathan P. Lanier and president Damien L. Goudreau paid themselves excessively and concealed pricey real estate purchases while withholding dividends.

Geoffrey Farrington, an attorney representing Granger, said the suit shows a “larger pattern and practice” of mistreating minority shareholders. Four other small shareholders have left in recent years — leaving the executives with a combined 98 percent stake.

The attorneys representing the brewery and its majority shareholders did not respond to requests for comment. As of Wednesday they had not yet responded in court to the complaint.

While shareholder lawsuits are common in the United States, they often focus on large, publicly traded companies with thousands of minority shareholders. In a small, closely held company like Tree House, experts said, there are special considerations that could come into play.

Unlike some other states, Massachusetts law views the joint ownership of Tree House as a “partnership,” said Boston College law professor Brian Quinn. “And in partnerships, every partner has a duty of utmost good faith and loyalty to all the other partners and shareholders in the corporation.”

Claims like Granger’s, that the majority stakeholders paid themselves large salaries and bought luxury cars, are “usually fairly weak,” Quinn said. However, the lawsuit may compel Tree House executives to explain decisions that Granger alleges did not benefit the company.

“If you’re doing your full duty,” Quinn added, “you don’t take opportunities at the expense of the other shareholders.”

Among the decisions described in the lawsuit are Lanier and Goudreau’s creation of two LLCs that they used to buy $13 million in real estate without Granger’s knowledge — namely land in Charlton and a beachfront home in Sandwich.

The lawsuit alleges that the holdings were only disclosed after Granger sent a demand letter in September 2022.

Pierluigi Matera, a corporate law scholar and Boston University professor, said that should the case reach trial, it will be on the company to prove that “those dealings were entirely fair.”

If the company can’t defend the purchases, Matera added, they could represent evidence of a breach of fiduciary duty of loyalty from the majority shareholders.

Jeff Lipshaw, a professor at Suffolk University Law School, said another key element of the lawsuit is its allegation that Granger and other former minority shareholders were deprived of “enjoying any real financial benefit from their ownership stake.”

Courts rarely expect that large, publicly traded companies would pay dividends to their shareholders (though many do). Lipshaw said, “It could well be a legitimate business decision to reinvest in growing the corporation, rather than paying a dividend.”

But at Tree House, the small number of shareholders, namely Granger, must pay taxes on their share of the company’s profits.

And “not paying dividends sufficient to allow the shareholders . . . to pay their taxes is a classic minority oppression technique,” Lipshaw said.

What comes next could have significant implications for a company that’s been a Massachusetts small business success story.

Since launching in 2011, Tree House has garnered wide acclaim from its five locations in Massachusetts and Connecticut. The company exclusively sells its brews on-site, making it “unique in its scale and success with the direct-to-consumer model” and the envy of small breweries in the region, said Adam Romanow, president of the Massachusetts Brewers Guild and founder of Castle Island Brewing Co.

Quinn, from BC, noted that lawsuits that involve a small number of shareholders with “enough time and enough emotional investment” sometimes last a long time and do not reach a settlement. That could be the case with Tree House, where Granger has been a minority shareholder for 11 years.

Lipshaw said the behavior toward Granger alleged in the complaint could also be an indication that Lanier and Goudreau are looking to “squeeze out” Granger from the company entirely.

Matera, from BU, added that litigation can also be a strategy by a departing shareholder to extract a bigger buyout. Airing grievances in public and raising questions about bad behavior can encourage companies to offer up more money during an owner’s exit than they otherwise would.

Farrington, Granger’s attorney, said his client just wants to be treated fairly by his partners.

“They need to answer for some of the things they’ve done,” Farrington added. “They put themselves in their position.”

Diti Kohli can be reached at diti.kohli@globe.com. Follow her @ditikohli_. Andrew Brinker can be reached at andrew.brinker@globe.com. Follow him @andrewnbrinker.