WASHINGTON XCast Labs, a company accused of helping make billions of illegal robocalls, was sued on Friday by the U.S. Federal Trade Commission, which asked the court to order the company to stop the practice.

XCast, a Voice over Internet Protocol (VoIP) provider, is accused of helping other companies, at least one of which falsely claimed to be a government entity, reach out to people on the National Do Not Call Registry and generally deceive them into making purchases or contributions, the lawsuit said.

The FTC requested an unspecified amount in penalties.

"XCast Labs played a key role in helping telemarketers flood homes with unlawful robocalls, including robocalls impersonating the Social Security Administration," said Samuel Levine, director of the FTC’s Bureau of Consumer Protection.

Representatives of XCast did not immediately respond to requests for comment.

The Justice Department filed the case on behalf of the FTC in district court in California.

(Reporting by Diane Bartz and Mike Scarcella; Editing by Bill Berkrot)