July 23 (Reuters) - Lindt has been sued in a U.S. court over its alleged use of child labor in Ghana and Ivory Coast, even as the Swiss chocolate maker touts its commitment to responsibly sourcing ingredients.

According to a complaint moved to the Washington, D.C. federal court on Tuesday, Lindt falsely assures consumers it is trying to eliminate child labor from its supply chain and is committed to children's rights and human rights generally. The complaint also said Lindt has known for more than 20 years that its cocoa is produced with child labor and profits from the practice.

"A reasonable consumer would not expect a company 'committed to respecting human rights' and 'conducting business in an ethical, legal and environmentally and socially responsible manner' to use widespread child labor in its cocoa supply chain," the complaint said.

According to the complaint, Lindt sources 100% of its consumer-grade cocoa beans from Ghana and sources cocoa butter from Ivory Coast.

International Rights Advocates, a public interest law firm, filed the lawsuit. It has also pursued cases accusing chocolate makers Mars, Mondelez ( MDLZ ) and Nestle of relying on child labor.

"Lindt & Sprungli takes the issue of child labor very seriously and strongly condemns all forms of child labor and denies the allegations in the complaint," a Lindt spokesperson said in an email on Thursday. "We have supplier protocols in place, and we systematically investigate suspected cases of child labor in our supply chain."

The Kilchberg, Switzerland-based company's website contains a 2030 Sustainability Plan that discusses Lindt's efforts to support cocoa farmers in West Africa and reduce risks from child labor.

Lindt also publishes a "Modern Slavery Statement" that discusses its "tailored strategy" to reduce the risks, including by honoring the Rainforest Alliance certification for farming practices.

The lawsuit seeks to end Lindt's alleged "unlawful conduct directed at D.C. consumers," and does not seek damages.

Terry Collingsworth, executive director of International Rights Advocates, said in an email that his research "confirmed that Lindt, like the other major cocoa companies, has great paper policies and virtually no implementation, particularly on the child labor issue."

His firm has also sued Apple, Cargill and Starbucks over alleged forced labor in their supply chains.