The Justice Department has opened an investigation into the cause of soaring egg prices, including whether large producers have conspired to raise prices or hold back supply, according to people familiar with the matter.

The high price of eggs and whether producers have conspired to raise prices is under investigation by the U.S. Department of Justice, the Wall Street Journal reported citing people familiar with the matter.

A report in The Wall Street Journal says DOJ investigators are looking into whether egg producers are working together to keep egg prices high.