A Blackwood man has been remanded in custody charged with possessing explosive materials, an improvised gun and a terrorist document.
Darren Tinklin, 24, of Waunllwyn Crescent, was arrested during a raid at his home on October 21.
He appeared at Woolwich Crown Court on Thursday charged with possessing gunpowder, potassium nitrate, charcoal, sulphur, and an improvised pipe bomb, made of copper tubing and tape.
Gwent Police arrested Tinklin and two others on suspicion of drugs offences after executing a warrant under the Misuse of Drugs Act.
After further inquiries, the Metropolitan Police Service Counter Terrorism Command was called and the trio were transferred to a central London police station for questioning.
They were arrested on suspicion of the commission, preparation or instigation of acts of terrorism under the Terrorism Act 2000.
The two other men, aged 24 and 41, were released without charge.
Tinklin will appear next at either Newport Crown Court or Cardiff Crown Court in January.