The FTC, DoJ and EPA are now coordinating their investigations.
The Federal Trade Commission has joined the Volkswagen criminal investigations, adding another potential source of fines and penalties if the agency finds evidence of wrongdoing.
The Environmental Protection Agency kicked off the inquiries, last month accusing the German automaker of installing a 'defeat' program in certain diesel-powered vehicles to cheat US emissions tests.
The Department of Justice later joined in to help determine if any emissions laws were broken and push the proceedings forward if charges are warranted. The FTC is now coordinating with its fellow regulators, presumably focusing on VW's "clean diesel" marketing.
"Diesel cars are really smelly, smoky and sluggish? That's in the past," reads an Instagram caption for a Golf TDI Clean Diesel advertisement, still posted in VW's social news feed, though most of the diesel marketing pages appear to have been removed from the official website.
"I am outraged that VW would cheat its customers by deceiving them into buying a car that wasn't what was advertised," Sen. Bill Nelson (D-Fla.) wrote in a letter to the FTC last month, as noted by Bloomberg.
Nelson has called for the agency to force VW to compensate consumers for the deception and launch a marketing campaign explaining the scandal and providing instructions for existing owners. It is unclear if the FTC will follow the enforcement recommendations, however.