Adds comment from attorney for petitioning group in paragraphs 5-7

June 22 (Reuters) - Three solar panel makers urged U.S. officials to investigate cell imports from South Korea, saying firms including Hanwha's Qcells 000880.KS, 009830.KS were using them to evade tariffs on Chinese products, according to a petition seen by Reuters.

The petition was filed with the Department of Commerce on June 18 on behalf of a manufacturing joint venture of Canadian Solar CSIQ.O, SEG and Heliene, which all operate solar panel factories in the United States.

The group, calling itself American Manufacturers for Energy Resilience, is seeking an anti-circumvention probe, accusing Qcells of shifting cell production to South Korea from China to avoid U.S. tariffs. Cells are the building blocks of modules, or panels, that convert sunlight into electricity.

Under U.S. trade law, tariffs can be extended to goods routed through third countries when processing there is minor.

An attorney for the group said it was seeking fairness.

"It is time that companies like Hanwha Qcells, that have been allowed to game both sides of U.S. trade law for far too long, are held accountable," attorney John Anwesen said.

"The AMER coalition is focused on leveling the playing field to allow fair competition across American solar manufacturers, and this circumvention inquiry request is a step towards that goal," Anwesen said in a statement.

Qcells has two solar factories in the U.S. state of Georgia and has a goal to manufacture all the key components that go into a silicon-based solar panel on U.S. soil.

Qcells, which has invested billions into its U.S. manufacturing operations, has been a driving force behind recent U.S. trade petitions targeting solar imports from countries in Southeast Asia. Some of those imports supplied factories owned by Canadian Solar, SEG and Heliene.

"Qcells has led the effort to reshore solar manufacturing in the United States, and we have a decade-long record of supporting strong trade enforcement, not evading it," Qcells spokesperson Marta Stoepker said in an emailed statement.

"We've reviewed this filing and are confident the evidence will show its claims are without merit."