A vulnerable autistic man is pleading with the UK government to block his extradition to the US on cybercrime charges where he faces a 52-year sentence for alleged offending that began when he was a child.

Diogo Santos Coelho, who has been assessed as at very high risk of suicide, said he had been groomed and exploited online by adults from the age of 14 into committing the alleged crimes, which relate to the website RaidForums.

Coelho is accused of being the administrator of RaidForums, described in court as “a marketplace for individuals to buy and sell stolen databases” with about 10bn stolen records.