Last month, officers from Counter Terrorism Policing North East (CTPNE) arrested a total of five men in Chesterfield and Sheffield in an operation supported by Derbyshire and South Yorkshire police.
Yesterday, CTPNE announced that a 21-year-old Sheffield man was released without charge.
A 41-year-old man and a 36-year-old man, both from Sheffield, were also previously released without charge.
As part of the investigation, Andi Sami Star, 31, of Sheffield Road, Chesterfield, and Farhad Salah, 22, of Brunswick Road, Sheffield, have been charged with engaging in the preparation of an act of terrorism.
Both men, who are Kurdish Iraqis, appeared at Westminster Magistrates' Court by video link from Leeds on Friday afternoon.
The court heard how they are accused of preparing to make a bomb for an alleged terrorist attack in the UK.
Thomas Halpin, prosecuting, told the hearing the Crown alleged that the pair had been in the early stages of a plot at the time of their arrests.
A lawyer for Mr Star - who owns the Mermaid Traditional Fish Bar on Sheffield Road, Chesterfield - said there was no evidence he was involved in terrorism and added that he would plead not guilty.
Mr Star and Mr Salah have been remanded in custody and are next due to appear at the Old Bailey in London on Friday, January 19. A CTPNE spokesman said: "Derbyshire Constabulary and South Yorkshire Police continue to work closely with their partners and communities to reassure local people and protect the public.
"If you see or hear something which could be terrorist related, act on your instincts and call the police in confidence on 0800 789 321.
"In an emergency, dial 999."
Visit www.gov.uk/ACT for more information.
The UK's terror threat level remains at 'severe', the second highest level.
Derbyshire police are urging people to continue to be vigilant but go about their business as usual.
Superintendent Michelle Shooter, of Derbyshire Constabulary, said: "We'd ask that people remain calm, resilient and measured in what they say and how they act during the aftermath of what has been a difficult and concerning time for local communities."