The senator also urged the department's Antitrust Division to review "with suspicion" any large mergers in the industry, after Cargill Inc and Continental Grain said in August they would buy chicken company Sanderson Farms for $4.53 billion, reported Reuters.

In a letter she said that consumers are paying higher prices because of excessive consolidation, price-fixing and "plain-old corporate greed."

According to US Labor Department data, prices for chicken breasts have jumped 26% over the past year. Similarly, turkey prices were up 24%, according to an annual American Farm Bureau Federation survey ahead of Thanksgiving.

The meat industry has said increased demand and the labor shortage have boosted prices. Four processors control 54% of the chicken market, up from 35% in 1986, according to the Biden administration.

"Lack of competition in the poultry industry is allowing these massive companies to squeeze both American consumers and farmers to fuel record corporate profits and payouts to shareholders," Warren said.

The Justice Department is investigating price-fixing among some chicken producers. The Biden administration is also promising a tougher stance toward four companies that control the US beef market as a way to rein in prices.

In February, chicken company Pilgrim's Pride Corp pleaded guilty and settled federal charges that it conspired to fix prices and passed on the costs to consumers.

A month earlier, Tyson Foods Inc settled civil litigation by three groups of plaintiffs that accused it of illegally conspiring to inflate chicken prices.

Warren asked the Justice Department to report by 20 December on how price-fixing and consolidation have contributed to higher poultry prices.

Republican US Senator Chuck Grassley previously raised concerns about the takeover of Sanderson Farms, the third-largest U.S. chicken producer.