** Shares of some health insurers fall after the Wall Street Journal reported, late on Wednesday, that the U.S. Department of Justice was investigating UnitedHealth Group UNH.N for potential Medicare fraud

** UNH said it had not been notified by the DOJ about the "supposed criminal investigation reported," and the co stood by "the integrity of our Medicare Advantage program"

** Shares of Medicare-focused insurer UnitedHealth Group UNH.N plunge 16.3%, Humana HUM.N slip 5.7% and CVS Health CVS.N down 2.2%

** Shares of Elevance Health ELV.N down 3.8%, Molina Healthcare MOH.N fall 3.5%, Centene CNC.N drop 3.7% and Cigna CI.N down 1%

** The US government's investigation into the alleged kickback scheme is part of a wider crackdown on the Medicare Advantage program, which has already led to lawsuits against other major health insurers earlier this month

** Including session moves, UNH down 48.6%, HUM down 14.3%, CVS up 30.7%, ELV down 2.3%, MOH up 2.8%, CNC down 5.5%, CI up 8.9% YTD

(Reporting by Kamal Choudhury in Bengaluru)

((Kamal.Choudhury@thomsonreuters.com;))