General Motors said in a filing with the Securities and Exchange Commission on Thursday that the automaker received notice of an investigation by the Federal Trade Commission concerning certified pre-owned vehicle advertising.

The notice — which came on June 3 according to the OEM’s document — stems from where dealers certified vehicles that allegedly still needed recall repairs.

“We continue to investigate these matters and believe we are cooperating fully with all requests for information in ongoing investigations,” GM said.

“Such investigations could in the future result in the imposition of material damages, fines, civil consent orders, civil and criminal penalties or other remedies,” the automaker added.

Auto Remarketing reached out to GM for further comment about the investigation, and company spokesperson Jim Cain said, "We are not elaborating on the disclosure."

When contacted by Auto Remarketing, Frank Dorman from the FTC’s Office of Public Affairs said, “Since an FTC investigation has been disclosed by General Motors, we can acknowledge the existence of the investigation, but have no further comment.”

The FTC matter arrives as General Motors is in the midst of a strong CPO sales year.

According to Autodata Corp., CPO sales for the Buick, Chevrolet, GMC, Pontiac and Saturn brands reached 34,777 units in June, representing a 20.2 percent rise year-over-year. Six-month sales for those certified brands came in at 224,292 units, marking a 20.7 percent gain.

The Cadillac brand had 2,007 certified sales last month, up 25.7 percent year-over-year with year-to-date sales reaching 12,767 units (up 26.2 percent).