The U.S. Department of Labor has sued a Duluth software company and its owner alleging employee contributions to the firm’s 401(k) profit sharing plan were not properly handled.

CSG Group Inc. and Thomas Wimberly face a civil lawsuit for allegedly violating the Employee Retirement Income Security Act (ERISA). The suit claims Wimberly and his company withheld more than $15,000 in employee contributions from 2005 to 2010, but never forwarded them to the plan. The funds were comingled with company assets, the suit said.

The suit also contends more than $163,000 in employee contributions were not timely forwarded to the investment plan in accordance with ERISA.

The suit seeks to recoup lost interest and opportunity costs of participants in the retirement plan. The Labor Department also seeks to appoint an independent party over the plan, which had 15 participants and nearly $400,000 in assets as of June 2010, according to a department news release.

A message left for Wimberly was not immediately returned.