Shares of Tyson and two other chicken producers fell on Tuesday after news that the U.S. Department of Justice is looking into potential price-fixing accusations.
The stock dropped more than 3% on the news and closed down 1.05%.
"We are aware of the Department of Justice's request, which does not change our view that there is simply no merit to the allegations that Tyson Foods colluded with competitors. We remain committed to vigorously defending ourselves against these baseless allegations," Tyson said in a statement to CNBC.
The criminal investigation also includes chicken producer Pilgrim's Pride and Sanderson Farms, according to Bloomberg, which first reported the probe. Pilgrim's Pride stock fell 1.25% and Sanderson dropped 2.22% on the news.
The DOJ intervened in a civil case against more than a dozen companies are being charged of conspiring "to fix, raise, maintain, and stabilize the price" of broiler chicken as far back as 2008, according to the complaint.
"Pilgrim's strongly denies any allegations of anti-competitive conduct. The company welcomes the opportunity to defend itself against these claims through the legal process," a spokesperson for Pilgrim's Pride told CNBC.
"[Sanderon Farms] has not been subpoenaed in connection with the Department of Justice investigation," Sanderson Farms said in a press release Tuesday. "The Company continues to believe the civil plaintiffs' claims as to Sanderson Farms are wholly without merit, and we are committed to defending the case vigorously."
—CNBC's Jim Forkin contributed to this report.