“The company and the individual defendants intend to defend themselves vigorously,” Vestas says in a statement.

The complaint has been filed in the Federal District Court for Colorado on behalf of the City of Sterling Heights General Employees Retirement Scheme and “all others similarly situated”.

It claims that Vestas “engaged in acts, practices and a course of business that operated as a fraud or deceit upon plaintiff and others similarly situated in connection with their transactions in Vestas”, between 27 October 2009 and 25 October 2010.