The Fair Trade Commission on Tuesday inspected around 20 locations related to camping and outdoor equipment maker Coleman Japan Co. on suspicion it forced retailers to maintain its recommended prices.

The Japanese unit of Coleman Co. of the U.S. said it will cooperate fully with the antimonopoly watchdog's investigation.

The firm is suspected of setting retail prices and discount limits for tents and other products, and forcing sports equipment stores and home improvement centers to maintain them, sources said.

When retailers refused to do so, Coleman Japan apparently threatened to stop shipping merchandise to them. The practice continued for several years, according to the sources.

Coleman Japan reportedly posted sales of about ¥11 billion in 2013.