UnitedHealth is again being accused of improper business practices for allegedly paying nursing homes to avert resident hospital transfers.

UnitedHealth Group has said it has not been notified by the Department of Justice of a reported criminal investigation. The Wall Street Journal reported on Wednesday that the firm is facing a DOJ investigation for possible Medicare fraud,

The Wall Street Journal on Wednesday cited people familiar with the matter as saying that the probe has been ongoing since last year.

The company has said in regulatory filings that investigations, audits and reviews by a dozen different government agencies are currently underway.

TD Cowen, Raymond James and Bank of America have all downgraded UnitedHealth’s stock, citing dogged internal challenges facing the company.

UnitedHealth Group (NYSE:UNH) is under investigation by the Department of Justice for potential Medicare fraud. The probe is centered around the insurer's Medicare Advantage business, The Wall Street Journal reported.

UnitedHealth has gone from bad to worse, and its drop is impacting the Dow Jones Industrial Average even more than it is the S&P 500.