Detroit-based watch and leathergoods manufacturer Shinola is to drop its 'Where American is Made' slogan after federal regulators ruled it "overstated the extent to which certain products are 'made' or 'built' in the United States."

In a letter to Shinola's parent company Bedrock Manufacturing Co, the Federal Trade Commission said some advertising materials from Shinola and its sister company, Filson, a Seattle-based outdoor clothing outfitter, could be misleading to consumers.

The FTC probe found 100% of the materials used to make some watches are imported, and that some belts contained 70% of imported materials such as "decorative buckles."

It recommended the company adds hangtags and information cards to affected products to alert consumers to the use of imported materials, redesigns watch casebacks, updates embossed claims on leather goods, and updates its advertising materials.

However, Tom Kartsotis, founder of Bedrock Manufacturing and Shinola, said the company would continue to mark its watches as 'Built in Detroit,' but will add 'with Swiss and Imported Parts.'

He added that the investigation highlighted inconsistencies in policies and laws, as well as the subjective nature of some of the processes governing 'Made in the USA' standards.

"Many of the components and raw materials are simply not available in the US, and because of that we are unable to meet the almost unattainable 'Made In USA' standards created by the government," he pointed out.