The U.S. Equal Employment Opportunity Commission has sued a national insurance company, contending the firm violated federal law by refusing to hire a North Carolina man after he disclosed he was participating in a methadone treatment program for a drug addiction.

The suit was filed Tuesday in U.S. District Court in Raleigh against United Insurance Co. of America, said EEOC attorney Lynette Barnes.

The complaint argues the firm violated federal disability discrimination law by refusing to hire Craig Burns, 30, who applied for a job in the firm's Raleigh office in December of 2009. The firm made a conditional offer of employment to Burns the following month, depending upon his passing a drug test, the complaint said.

The test showed the presence of methadone in his system, so Burns submitted a letter to the firm from his treatment provider saying he was participating in a supervised methadone treatment program and taking legally prescribed medication as part of the treatment, the complaint said.

Upon receiving this information, United Insurance notified Barnes he was not eligible to be hired and withdrew the employment offer, the complaint said.

Barnes said the action violates the Americans With Disabilities Act, which protects employees and applicants from discrimination based on their disabilities. A recovering drug addict is covered under the act, the attorney said in an interview.