The former JPMorgan Chase & Co trader who became known as the "London Whale" as his unit generated $6.2 billion (£4.4 billion) of trading losses in 2012 said he is not to blame for the scandal and was made a scapegoat for decisions made by his superiors.  (See http://www.futuresmag.com/2014/08/31/london-whale-rogue-risk-management )

In a roughly 2,100-word letter sent to media on Monday, in which he broke nearly four years of silence, Bruno Iksil said he had been "instructed repeatedly" by senior management in the bank's chief investment office (CIO) to execute the trading strategy that caused the losses.

Iksil, a French national who traded credit derivatives for JPMorgan in London, also said he objected to being called the London Whale, and being portrayed by media as solely responsible for the losses.

He said he had in the summer of 2011 repeatedly warned colleagues about the trading strategy, and by early March 2012 was "raising alarms" over management's plan to add even more risk. Losses began to publicly surface in early April 2012.

"The losses suffered by the CIO were not the actions of one person acting in an unauthorised manner," Iksil wrote. "My role was to execute a trading strategy that had been initiated, approved, mandated and monitored by the CIO's senior management."

JPMorgan declined to comment on Tuesday. Lawyers for Iksil in the United States on Tuesday confirmed the authenticity of the letter. 

The scandal hurt the reputation of JPMorgan Chief Executive Jamie Dimon, who at first downplayed the losses as a "tempest in a teapot" before changing course.

JPMorgan ultimately paid more than $1 billion and admitted wrongdoing to settle U.S. and British probes into the losses.

In 2013, the U.S. Department of Justice decided not to prosecute Iksil over the losses.