Anheuser-Busch has stepped into a labour dispute in its home city of St Louis. The brewer has filed unfair labour practice charges against members of the Teamsters Union involved in a dispute with Lohr Distribution in the city.

AB alleges that the Teamsters' members have encouraged the employees of third parties to boycott the brewer's products, thereby forcing AB to enter the row.

The National Labor Relations Board will investigate the allegations and ascertain whether there is reasonable cause to believe that the law has been violated.

By pushing for a boycott of AB, the International Brotherhood of Teamsters are violating US labour laws, the brewer claims.

The workers, who have been on strike since 22 May, say they are fighting Lohr's plans for lower wages, the elimination of full-time jobs and an increase in health care costs.