The Department of Justice is considering egg prices for antitrust probes, according to the report

The U.S. Department of Justice has launched an investigation into potential antitrust issues related to egg surges, the Wall Street Journal reported Friday, citing people familiar with the issue.

The study includes early stages of research to see whether large egg producers work together to raise prices or lower supply, the report says.

The news leads egg prices to skyrocket and several restaurants to announce changes and reports of grocery store menus on empty shelves. For example, Denny’s announced last month that it was taking over the rise in egg costs to its customers in the form of extra charges.

In the latest Consumer Price Index Report, data from the Bureau of Labor Statistics showed egg prices, up 53% from the previous year. On a seasonally adjusted basis, egg costs rose 15.2% between December and January. This marks the largest increase in the egg index since June 2015.

The price rise appears to be at least in part due to the outbreak of avian flu, which has led to egg producers culling the population. However, the advocacy group’s farm action last month sent a letter to the DOJ and the Federal Trade Commission asking for an investigation into other causes.

CNBC has not independently confirmed that this investigation is ongoing. The Department of Justice did not immediately respond to requests for comment.