LONDON (Reuters) - Tom Hayes, the first person worldwide to be jailed for conspiring to manipulate Libor interest rates, on Monday night launched a last-ditch appeal against his conviction and 11-year sentence in Britain, alleging his trial was unfair.

Former trader Tom Hayes arrives at Southwark Crown Court in London, Britain July 29, 2015. REUTERS/Suzanne Plunkett/File Photo

Hayes, a gifted mathematician with mild Asperger’s syndrome, was initially sentenced to 14 years in prison in 2015 for conspiracy to rig the London interbank offered rate (Libor), a benchmark for rates on around $450 trillion worth of loans worldwide, while working as a Tokyo-based trader for UBS Group AG and Citigroup Inc from 2006 to 2010.

The sentence - one of the longest for white-collar crime in Britain - was reduced to 11 years on appeal. But his attempt to overturn his conviction failed and London’s Court of Appeal blocked any further appeal at the Supreme Court.

Hayes, backed by his family and supporters, has lodged a fresh appeal bid with the Criminal Cases Review Commission (CCRC), which looks at miscarriages of justice, after raising around 78,000 pounds ($97,000) through crowdfunding.

The CCRC, an independent body, can refer a case back to the appeal courts on the basis of compelling new evidence or legal argument.

“It is clear from the evidence I have obtained that Mr Hayes has been the subject of a gross miscarriage of justice and I am confident that the CCRC will agree and refer the case back to the Court of Appeal,” Karen Todner, a human rights lawyer representing Hayes, said in a statement.

Todner said this view was supported by leading experts on Asperger’s, who issued a joint statement saying Hayes’s conviction “raises real concerns about the treatment of autistic people in the criminal justice system”.

Professor Richard Mills, a director of autism training and consultancy organization AT-Autism, said he did not believe Hayes met a legal test for criminal responsibility that hinges in part on a defendant’s understanding of whether others would regard their conduct as dishonest.

Hayes was presented by prosecutors as a formidable and unscrupulous ringmaster in a global conspiracy with staff from at least 10 banks and brokers to fix yen Libor - rates designed to reflect the cost of bank-to-bank borrowing - for profit.

Hayes, now 37, denied dishonesty and argued during his trial that his actions were both condoned by bosses and common practice at the time and said his Libor requests fell within an acceptable trading range. He has accused prosecutors of not providing evidence to the jury to help him prove his case.

In a statement released late on Monday, Hayes said he had uncovered fresh evidence that demonstrated that Libor rates could be set commercially and alleged he had been coerced into making false confessions by investigators.

He also alleged that the Serious Fraud Office’s (SFO) failure to properly investigate UBS and Citigroup allowed evidence he needed for his defense to be suppressed and that the agency had failed to disclose evidence of central bank involvement in the Libor rate-setting process.

He labeled as “absurd” an argument by an SFO lawyer in his trial that there was no trading range for interbank cash and alleged the agency attempted to deny the jury any knowledge of his Asperger’s diagnosis.

“I continue to maintain my innocence and it is my case that I did not have a fair trial,” he said in a statement signed from HMP Lowdham Grange prison in central England.

The SFO declined to comment.