McDermott Will & Emery's UK arm is being sued by an investment fund manager over claims of fraudulent misrepresentation and breach of fiduciary duty.

The claimant, investment manager David Gorton, alleges that two former McDermott London lawyers advised him to invest in carbon credit trading schemes that they had undisclosed personal financial interests in.

The two lawyers, Alistair Wilson and Menna Bowen, formerly worked in the US firm's City tax practice. They have both since left McDermott and are now at UK firm gunnercooke.

The claim states that McDermott began providing tax advice to Gorton in 2004, and that in 2005, he and his business partner met with Wilson to discuss "tax structures and associated investment opportunities".

Wilson suggested that he invest in a series of limited liability partnerships (LLPs) which created and traded carbon credits – described in the court documents as the "Carbon LLPs" – which were managed by a company named Carbon Capital Limited (CCL).

Gorton claims he was advised that "significant tax relief" would be available to investors and, relying on McDermott's advice, invested £38m in five Carbon LLPs, including £7.6m in cash.

The claim states that Wilson and Bowen were members of an LLP which meant they stood to receive a share of the profits of each of the Carbon LLPs. It alleges that McDermott was in breach of its fiduciary duty, as Wilson and Bowen did not sufficiently disclose their financial interests in these schemes.

In 2006, HM Revenue & Customs (HMRC) began an enquiry into the tax affairs of the Carbon LLPs, followed by a 2007 fraud investigation into CCL's directors and executives. HMRC has not not paid the claimants any of the expected tax relief, and the claim states that "it currently appears that the claimants will lose the entirety of their initial capital contributions of £7.6m".

Gorton claims that "but for the breaches of duty and fraudulent misrepresentation, he would have not invested in the Carbon LLPs".

As well as damages for fraudulent misrepresentation and breach of fiduciary duty, Gorton is claiming statutory compensation, interest and costs.

He is being represented by Fieldfisher tax disputes head Hartley Foster, who has instructed 3VB's John Jarvis QC and Matthew Parker.

A McDermott press spokesperson said: "McDermott Will & Emery is aware of the claim made against us in relation to two former employees who had left by 2009. The firm doesn't comment on ongoing matters."

gunnercooke was approached for comment.