Ex-trader convicted of rigging LIBOR claims authorities had a 'lack of understanding' and a 'flawed case'
Hayes was initially convicted and sentenced to 14 years in prison last year, but had his sentence reduced to 11 years on appeal, and is now crowdfunding for a further legal challenge, raising more than £77,000 at the last count.
Former UBS and Citigroup trader Hayes - who suffers from Asperger's Syndrome, something he has frequently cited when criticising his conviction - sent a letter this week from his prison cell, calling out the SFO and FCA for allegedly "to conduct independent investigations" into LIBOR rigging, according to a report by the Financial Times.
In his letter, Hayes also attacked the Bank of England for allegedly being complicit in the so-called "lowballing" of LIBOR submissions, which in Haye's words "involved the submission of inaccurate Libor rates which were not drawn from within the market trading range, and which were therefore false."
"Lowballing was not done at the behest of traders, but rather senior management of banks with the involvement of the Bank of England," Hayes wrote, before calling on the SFO to undertake a "wide ranging investigation" into the practice.
That allegation comes in the same week that the FT reported several senior Barclays employees, both current and former, have been called in by the SFO for questioning about whether Barclays was previously involved in the practice of "lowballing."
LIBOR - or the London interbank offered rate - is the daily measure meant to show the rate at which banks will lend to each other and is used to set the price of hundreds of trillions of dollars worth of financial products.
Hayes, a 36-year-old former UBS and Citigroup derivatives trader, was held up as an example to errant bankers when he was convicted last August of masterminding a conspiracy to distort LIBOR to suit his trading book.
However, Hayes has consistently argued that he has been held up as a scapegoat, and has made several attempts to try and clear his name.
He is not the only convicted former LIBOR trader to hit out at the SFO and FCA, with Julie Pabon, the wife of convicted former Barclays trader Alex Pabon - one of four convicted over the summer - writing this week: "My concern is that this investigation is merely a limited probe of certain, specific individuals conducted in order for the SFO to save face in light of the recent claims that senior management was involved with Libor 'manipulation'."