According to the news service, Merrill has filed a lawsuit with the New York Supreme Court claiming that Mr Heaton - who resigned at the beginning of February - failed to adhere to his required notice period, and violated a non-compete clause which restricted him from joining another bank until February 2010.

Merrill’s complaint also refers to 11 other staff in addition to Mr Heaton, all of whom resigned on the same day.

The report quoted Merrill’s filing as having said: “It is readily apparent that Deutsche Bank conspired with one or more of Merrill Lynch’s departing employees.”

Among the hires made by Deutsche was Alex Heaton’s brother, David Heaton, previously Merrill’s head of global asset management investment banking.

Merrill also claims that Deutsche misappropriated trade secrets through its hire of Eric Heaton, including information about its “business operations, liquidity, funding sources, clients and corporate strategies.”

The report quotes Jack Gordon, a lawyer for Merrill Lynch, as having said: “Merrill is seeking $100 million in damages suffered in the event that we prove there has been a breach of duty of loyalty and fiduciary duty.”

A hearing for the case has been scheduled for 16 March; meanwhile, Deutsche Bank has agreed to put off Eric Heaton’s hire for 90 days until a judgement has been reached.

Deutsche Bank declined to comment when contacted by WealthBriefing.