Ilfracombe cyber security expert Marcus Hutchins is facing four new charges in America for alleged cyber crime.
Mr Hutchins, who was hailed a hero after being credited with stopping the Wannacry virus, was charged last August with six charges of creating and selling the Kronos malware designed to steal banking details.
Now federal prosecutors have added four new charges alleging he created a second piece of malware, known as UPAS Kit.
New court documents filed on Tuesday also allege he lied to the FBI.
His lawyer Brian Klein tweeted the charges were ‘meritless’ and added ‘It only serves to highlight the prosecution’s serious flaws’.
Mr Hutchins, also known as Malware Tech, now faces 10 charges of computer fraud and trying to access computers without authorisation.
Last year he was accused of creating and distributing the banking trojan between July 2014 and July 2015 alongside another defendant, identified in the latest court documents as ‘Vinny’ or ‘VinnyK’ among other aliases.
Mr Hutchins, who works for Los Angeles-based computer security firm Kryptos Logic, was freed on a 30,000 US dollar (£23,000) bail.
To help pay his legal bills, friends have launched a crowd funding campaign called Support MalwareTech which has so raised $22,300 of its $25,000 target.
In May 2017 he was hailed a hero for curbing the WannaCry ransomware attack that infected more than 300,000 computers in 150 countries and crippled the NHS.
He said at the time his initial bid to stop the virus was ‘accidental’ and it prompted worldwide recognition and coverage across national newspapers and television.