The U.S. Department of Justice has joined a whistleblower lawsuit against Fresenius Medical Care AG, the world’s largest dialysis care company, which accuses the company of defrauding Medicare between 1999 and 2005 by filing false claims.

Two former employees filed suit against the company, contending that the fraud was an attempt to skirt Medicare’s policy of paying companies that sell dialysis supplies only if the company is independent of a dialysis facility. The Renal Care Group and Renal Care Group Supply Company, both German firms acquired by Fresnius last year, allegedly set up “sham” businesses and submitted false claims and bills to the government.

This case could stand to match or beat a similar suit filed against rival DaVita Inc.’s Gambro Healthcare a few years back – that company paid $350 million, one of the government’s largest health care fraud settlements, to settle accusations of fraudulent “shell” companies used to supply dialysis equipment.

Commentary: Recently, German corporations have been getting a five-alarm wake-up call about corporate compliance and fraud.