Mercy For Animals is a nonprofit dedicated to animal welfare that is best known for publishing investigative, undercover videos. The group published its latest video on Wednesday, this time targeting leading egg distributor Eggland’s Best.

The footage was obtained by an MFA investigator who went undercover at Briarwood Farms, a supplier for Eggland’s Best, between February 29 and May 12, 2016. The whistleblower worked at nine Briarwood facilities, each one containing tens of thousands of birds according to MFA estimates.

What he saw was disturbing. Birds fall into manure pits where they get stuck for days without food and water, essentially just waiting to die; they are physically abused by the workers; and on a daily basis you can see dozens of dead hens strewn amongst those still laying eggs, which could potentially be a breeding ground for disease. In fact, studies have found that there’s an increased risk of salmonella in caged egg production.

Conditions were so bad that MFA filed a criminal complaint against Briarwood with the Thurston County Sheriff’s Office in Washington, where the facility is based. The complaint, obtained by Fortune, accuses workers at Briarwood Farms of first degree and second degree animal cruelty. It cites numerous instances in which chickens were forcefully hit over the head with various objects, including a metal scraper tool and a broomstick, and details how they mishandled the hens by “roughly grabbing them by a single wing and violently shoving them into garbage cans”—which can be seen in the video.

https://www.youtube.com/watch?v=Dt8Zs3C4G-E

A statement by Briarwood Farms vice president Mark Oldenkamp said that they are not taking this video lightly. “We have noted several instances of hen mishandling in the video, and I am deeply disappointed to see those actions,” Oldenkamp said. “Upon learning about the video, we immediately began an internal investigation and initiated requests for prompt and rigorous independent reviews.” He added that a third party audit by UEP Certified is already under way.

Criminal complaint aside, the video is focused on Eggland’s Best rather than Briarwood, ending the video by saying, “Join me in urging Eggland’s Best to end this disgusting animal abuse.” It positions the egg producer as being behind in transitioning from caged eggs to cage-free.

While MFA notes that other large companies like McDonald’s, Kroger, and Walmart have committed to going cage-free within the next decade, Eggland’s Best would actually be the first egg producer to do so. So far only retailers and restaurants have made that commitment.

According to Bart Flaugh, Eggland’s Best director of quality assurance, the company is actually ahead of its peers. The rest of the egg production industry averages about 10% cage-free eggs; for Eggland’s Best, it’s 20%. Flaugh added that the company is working to expand its cage-free production, though the market can’t currently support a total transition.

As for the video, Flaugh called it “disturbing,” and said that the company is investigating the matter thoroughly. Briarwood, which supplies Eggland’s Best with “1% or less” of its eggs, has been a supplier for over 20 years, and so far it has had a “flawless record” regarding animal care and passing audits. While Flaugh said that “it’s hard to totally discredit them as a supplier after all these years,” if it turns out that the video actually is representative of the farm workers’ conduct, “they would be discontinued as a supplier. We just can’t tolerate any animal abuse.”

However, Flaugh did express some skepticism about the video saying, “It seems a little bit like this is a set up.” He said that MFA had contacted Eggland’s Best numerous times prior to publishing the video. The company was told that if it publicly commited to cage-free eggs, then the narration would be spun in favor of Eggland’s Best by telling the audience that the egg production company was making the effort to transition to cage free; if not, it would be spun the other way.

When asked about Eggland’s Best’s accusation, MFA responded with the following:

We believe consumers have a right to know where their food comes from and how animals at Eggland’s Best suppliers are treated so they can make informed choices. That is why we released the video and are calling on Eggland’s Best to stop supporting blatant animal abuse in its egg supply chain by committing to going 100% cage free. If Eggland’s Best does commit to taking this stand against animal abuse, of course we would praise them. Until then, we will continue to let their customers know that Eggland’s Best eggs come from tortured hens.

A previous version of this article stated that the MFA investigator worked at one Briarwood Farms facility with about 20,000 hens. He actually worked at nine facilities, each one with tens of thousands of birds.