Ryan O’Donnell, 37, stored the substances, including potassium nitrate, nitrogen and sulphur, at his Edinburgh home. A rocket diagram plan was discovered alongside notebooks which contained handwritten instructions that would allow an individual to prepare viable, high explosive substances.

O’Donnell was sentenced at the High Court in Edinburgh after pleading guilty to offences connected to homemade explosives.

He also admitted possessing almost 1,500 indecent images of children and has been placed on the Sex Offenders Register for 10 years. Police also recovered three computer tablets which were later found to contain 1,492 indecent images of children between the ages of six and 14.

He will be supervised by the authorities for 12 months following his release from custody.

Moira Orr, who leads on major crime for the Crown Office, said: “The substances that Ryan O’Donnell had in his possession could have been used to manufacture improvised explosive devices.

“They would have had the potential to cause significant harm to individuals and damage to property if used for criminal purposes. This case also demonstrates our commitment to prosecuting sexual offenders, using every tool at our disposal to secure justice.”