A 17-year-old youth has appeared in court in Newtownards, Co Down charged with possession of items likely to be of use for terrorist activities.
Mr Alan Robert Ferguson, of West Link in Holywood, was accused of possessing four balaclavas in suspicious circumstances.
Mr Johnston, who replied "not guilty" when charged, was remanded in custody until October 17th.
It is understood the charges relate to the murder of Jim Johnston, a senior member of the Red Hand Commando, an organisation with close ties to the Ulster Volunteer Force.
Mr Johnston (45) was shot dead outside his home on the edge of the village of Crawfordsburn, Co Down on May 8th.
Police said at the time they believed the murder could have been the result of a falling out among loyalists over drugs.