The U.S. Department of Justice is looking into beef prices. It has sent letters to several big retailers, asking for information about recent price increases.

These retailers include Walmart, Costco, and Kroger, among others. The investigation is trying to figure out if some companies are doing things that are not fair to others. It is part of a bigger effort to understand the beef supply chain.

More information is available from the source about this investigation and the companies involved.